Danny is having a really bad day. First, he forgets his wallet. So his parents show up at the Nasty Burger to drop it off... moonwalking, dressed for 80s Night, and speaking Totally Radical. When he runs outside to recover from that attack of embarrassment, Plasmius shows up. The two barely exchange opening remarks before he tosses a canister at Sam and Tucker that releases a purple gas; when it clears, their faces are covered with the same ecto-acne Vlad's Freak Lab Accident gave him in college. And no, he's not Carrying the Antidote; in fact, he doesn't even know what the antidote is. That's what he wants Danny to find out, because he's had a relapse and needs someone to Find the Cure! for him — which Danny now has to do if he wants to save his friends.
Jack and Maddie take all 3 patients to the ops center and give Fenton Works the full HazMat treatment. Danny's sure his parents can do something about this, but their hopes aren't high; his mom says they can't treat it until they can identify the impurities causing the "lethal acne" (for the record, Tucker and Sam are as shocked that acne can be "lethal" as we are). Danny's ready to kill Vlad for doing this to his friends, but his enemy smugly tells him he should focus on finding a cure, as his friends are "running out of time." The phrase gives Danny a Eureka Moment — he thinks he's found the perfect way to fix this.
Clockwork disagrees. Danny shows up at the Time Master's lair and asks him to send him back in time to Vlad's accident so he can stop it — if Vlad never gets his powers, Sam and Tucker will never get sick, and the world will be a safer, better place for everyone. Clockwork warns him that he's not thinking this through, that meddling in the past can have consequences he can't foresee, doing more harm than good, but Danny's willing to take the risk. Clockwork accepts that he's bent on learning this the hard way and grants his request. He opens a portal to the University of Wisconsin twenty years ago and sends Danny through (time medallion no longer required, for some reason...).
Danny's still in ghost mode when he arrives in the past, but, fortunately, the locals find his outfit "totally awesome." Thanks to a nearby bulletin board advertising a ghost portal experiment, he has no trouble locating his target. He flies across campus, intangible and invisible, to the science lab indicated on the flier, where he finds his parents, Vlad, and the prototype ghost portal, yet to be activated. Vlad keeps trying to tell Maddie something, but she's busy with the portal, checking the calculations and reminding Jack to fill the filtrator with ecto-purifier. Jack doesn't look very carefully at what he picks up and grabs a can of Diet Cola by mistake, but nobody except Danny notices him pour it into the filter.
Everything's ready. Vlad looks more closely at the portal and tells his friends it won't work. The rest of the flashback shown in Bitter Reunions plays out, from Maddie noticing the calculations aren't right to Jack throwing the switch to the malfunction... except, this time, Danny flies forward and pushes Vlad out of the way. The blast of ectoplasmic energy ricochets around the lab, almost hitting Maddie at one point, but Vlad pushes her down at the last second. Danny shields his eyes from the glare and doesn't see what gets hit when the explosion finally occurs. When he opens his eyes, Maddie's thanking the still very-human Vlad for saving her life. Perfect! "No ecto-acne, no Plasmius... mission accomplished."
Clockwork, watching from his lair, takes this as his cue to bring him back and teleports Danny back to present-day Amity Park. At first, Danny thinks everything's been fixed, until he notices that not only is the HazMat tent gone from his house, but so is the ops center. He powers down to human form and goes inside, where he finds the place a complete mess and no sign of his family. When his dad runs in and yells at him for trespassing, it's hard to tell who's more confused: Jack, when the boy calls someone who's single and has no kids "Dad"; or Danny, when he sees that his father, who doesn't recognize him, has ecto-acne. Jack freaks out when he mentions this, as he shouldn't know something like ecto-acne even exists. Danny now realizes exactly how he changed the accident, but the full result doesn't become clear until his dad goes ghost and starts attacking him.
As Danny runs from his attacks, he keeps insisting he's his son, and Jack keeps insisting he doesn't have a son. Danny finally goes ghost himself, which only makes Jack more enraged than surprised: "You're a ghost? I HATE GHOSTS!" Most of the living room gets destroyed as Danny dodges a barrage of energy blasts. He ends up crashing through the floor, landing in the basement, where he decides he's had enough he's ready to go ask Clockwork to undo his undoing of the past. Only one problem: no portal. He's looking around the cobweb-covered lab when he spots a terrible, devastating sight pinned to the wall: a newspaper article on the marriage of the new Wisconsin Dairy King (Vlad Masters) to his college sweetheart (Maddie). What has he done?! Danny's horrified to discover just how badly he's destroyed the past, present, and future!
Danny's still staring in horror at the photo of Mr. and Mrs. Vlad Masters when Jack comes after him. He's about to shoot another blast at him when Danny shows him the article and all the fight goes out of him. Danny begs "Jack" to tell him what happened after the accident. Unable to resist an invitation to blather on about his past, Jack tells him how the explosion gave him a severe case of ecto-acne and ghost powers, whereas Maddie fell in love with Vlad after he saved her. As Jack lost the love of his life that day, he tried to find a new path, but he was hopelessly unsuccessful as a ghost-fighting super hero. He finally moved here to continue his research and try to find a cure for his condition, but he never did: "No matter how hard I tried, I couldn't get rid of my ghost half... the half I knew Maddie would never be able to accept."
Danny knows this is all his fault and says so, which doesn't make any sense to Jack. Danny takes out his wallet, which has remained unchanged along with him, and still contains a picture of him with his parents and sister. Jack is completely speechless when Danny shows it to him and tells him he, not Vlad, was supposed to marry Maddie, that Danny wrecked everything when he traveled back in time and interfered with the accident. Once he's done, Jack's temper begins to come back. When Danny says he thinks he could fix everything if he had a ghost portal, the now furious Jack calls him a liar, splits into four, and blasts him out of the house.
Danny crashes hard into a familiar billboard and falls onto the roof below, in bad shape after that last attack. Not up to any more fighting, he simply turns invisible when Jack comes looking for him and waits quietly until he leaves. Now he needs a plan. He can't fix this without Clockwork's help; he has to find a way back to the Ghost Zone. Since his dad doesn't have a portal, that just leaves his mom. Knowing it's a long shot but his only shot, he takes off for Wisconsin.
The exhausted ghost boy turns human the instant he lands outside Vlad's castle an unspecified amount of time later. He manages to knock on the door, but as soon as Vlad and Maddie answer, he mumbles, "Mom," and collapses to his knees, wiped out by his long flight. At least it prevents him from immediately needing to answer any questions about what he's doing here.
It's not until later, after Vlad and Maddie take him in and bring him some food, that Maddie asks him where his parents are. Danny cryptically explains that "there was an accident" and now his parents are "missing." Both husband and wife are sorry for him and ask if there's any way they can help. As they lean in for a kiss, Danny, desperate to kill that moment before it can start, hurriedly asks apropos of nothing if they have a ghost portal. Maddie looks uncomfortable but tries to dismiss it as a silly question. Vlad also assures him, "We do not discuss GHOSTS! In! This! House!" Danny finds that odd, as he notices a weapon he recognizes as an ecto-foamer in a nearby closet. Maddie insists it's just a carpet foamer, and a relieved Vlad takes her word for it, so Danny is forced to endure the scarring sight of Vlad making out with his mother.
The picture doesn't make sense to Danny. He refuses to believe his mom would give up ghost hunting, no matter what universe she's in, and he flies around the castle that night in ghost mode, looking for answers. He finds the lab where Vlad trapped him after they first met back in his own timeline but nothing suspicious there or anywhere else. He finally finds what he's looking for on some floor below that: a lab with a ghost portal... pink and shaped like a heart, but good enough to get him back to Clockwork. His Hope Spot is brought to an abrupt end when Maddie, dressed in her jumpsuit and goggles, appears behind him and sucks him into the Fenton Weasel (which still exists in this universe under the moniker Maddie Weasel).
Danny regains consciousness to find himself Strapped to an Operating Table in a Crucified Hero Shot. Keeping a laser trained on him, a highly suspicious Maddie asks what he's doing in her secret lab. Danny panics as he comes within an inch of being fried and screams for her to stop, but Maddie couldn't care less, as her lab is completely soundproof ("It has to be, or my husband would find out about it"). Pointing the laser at him again, she demands to know who he is. With no time to think up any plausible story, Danny just tells her the truth — he's her and Jack Fenton's son.
Maddie, of course, doesn't believe that any more than Jack did. She hasn't even seen Jack Fenton since the day he got his powers twenty years ago; she and Vlad had to move all the way out here to hide from him, since he blamed her for his accident. Danny's livid when he hears such a crazy story and tries to tell her that nothing could be further from the truth, that he still loves her. Before Maddie can react to this claim, Jack Fenton himself appears in ghost mode and tells her it's true. Maddie's shocked to see him.
He returns to his human form and shows her what made him come here after all this time — Danny's photo of the two of them married with kids. Maddie chokes up at the sight, at the thought of having a family with the man she's always loved. Once she stops crying, she throws her arms around him, and he hugs her back. Maddie quickly releases Danny, overjoyed to meet their son from an alternate timeline, and the three share a family hug, Danny grateful that parents who hunt ghosts don't bat an eye at the possibility of alternate timelines or visitors therefrom.
All three of them are now equally eager to reset time back to the way it should be. Maddie pulls up her file on Clockwork on one of the lab computers and powers up the portal. Jack looks forward to living in a universe where he has two kids with Maddie as Danny prepares to leave... only to be stopped by an irate Vlad, armed with Chekhov's Ecto-Foamer. Maddie nervously tries to tell him its Not What It Looks Like, but Jack announces that this is exactly what it looks like as he goes ghost: "You and I are destined to be together, and nothing will keep us apart any longer!"
Vlad responds by sticking him to the wall with a blast of ectoplasmic foam. Danny flies at him, and Maddie accidentally gets blasted in the ensuing fight. Danny gasps, "Mom!" before firing an energy blast at Vlad, who tells him to never call her that again. His shot knocks Danny back down to the table, where the restraints automatically clamp down on him, holding him in place. Vlad turns on the laser and prepares to get rid of his unwelcome guest. Danny tries to tell him this is all wrong, that nothing was supposed to be this way and none of this should have happened, but Vlad doesn't care — he likes his life the way it is, and he's not going to let anybody change it!
Jack hurries over and pushes Vlad away from the laser before he can hurt Danny, but Vlad gets right back up and turns the weapon on him. Jack protects himself with a shield, but the force of the blast knocks him back against the portal. The combined energy of the portal, the laser, and the shield cause another explosion, and Jack's lying on the floor in human form when the smoke clears. Maddie rushes over to him, but he tells her not to worry ("Just remember what could have been...") before he either passes out or dies.
Maddie completely loses it now, but neither her anger nor her rant does anything to wipe the smug grin from her husband's face, until she grabs him and flings him right through the portal. While Vlad takes in the circle of ghostly monstrosities surrounding him, Maddie releases Danny. They don't have much time before the portal overloads, and the only way they can fix things is if Clockwork sends Danny back in time to make sure none of it happens. As soon as he's free, Danny flies straight at the portal; he just barely makes it before it explodes.
Danny makes it to Clockwork's with no problem, but if he had any hopes of redoing his visit to the past to get better results, it's clear he'll have to forget about them. He wants to prevent the horrible future... er, present(?) he just saw, but he still wants to save Tucker and Sam, as well. Clockwork will have none of it; he'll reset time to its original state before it was altered, but Danny will have to cure his friends in the present without changing things that already happened. He does, however, let Danny watch the scene as it unfolds, zooming in on Jack as he pours the Diet Cola into the filter. Danny jubilantly realizes, "That's it!" before he rushes to return to his own time, Clockwork grinning in satisfaction behind him. (That must be another direct violation of the Protocol of Temporal Displacement!)
Danny arrives back in Fenton Works just in time to cut off Sam before she can ask Maddie to tell Danny something for her. Before his mom can panic for too long about him coming in without protective gear, Danny asks her if the unknown impurities are consistent with Diet Cola. Maddie thinks that's ridiculous, at first, but gasps in surprise when she checks a read-out with this new theory in mind.
Sure enough, she and Jack concoct an antidote that, after their patients drink it, removes the impurities instantly, completely curing the ecto-acne. Maddie's deeply impressed that Danny figured it out, but he dismisses it as a side-effect of being raised by the world's smartest ghost hunters. And after what he's been through, it's safe to say he'll never fail to appreciate his parents again, all their weirdness notwithstanding.
This episode provides examples of:
- Agent Mulder: Jack and Maddie may find the fact that the other loves them hard to believe, but that you're their son from an alternate timeline? No problem.
- Almost Kiss: Vlad was about to do this after he saved Maddie from the portal explosion.
- Alternate Timeline: Danny creates one after saving Vlad from getting hit with the ectno virus. Danny does not like it.
- Blatant Lies: Vlad's entire relationship with Maddie is based on these.
- Borrowed Catch Phrase: Vlad borrows Jack's "...molecule by molecule" Catchphrase.
- Brain Bleach: Danny wishes he had some after he sees his mom kiss Vlad.Danny: And I thought my real parents were embarrassing. This is so much worse!
- The Bus Came Back: After being featured heavily as the Big Good in "The Ultimate Enemy", Clockwork returns to help Danny on his quest as a Trickster Mentor. Of course, after this episode, he wouldn't be featured again, in a Long Bus Trip that lasted up until the series finale.
- Butterfly of Doom: Changing one instant in time causes a runaway chain of Disaster Dominoes. Danny even points this out when he explains it Alt!Jack.
- The Chessmaster: It's safe to assume that Clockwork knew exactly how everything would turn out when he allowed Danny to return to the past.
- Despair Event Horizon: Alt!Jack experienced this when the accident happened to him instead of Vlad.
- Fantastic Aesop: You can't use Time Travel to solve your problems — it always makes things worse.
- Gallows Humor:Tucker: I can't be a goner! I haven't even dated a cheerleader yet!Sam: Trust me, you're never gonna live that long.
- Gilligan Cut: Clockwork does this twice (must be easy, when you're a Time Master).Danny: That gives me a great idea.Clockwork: No, it's a horrible idea.LaterMaddie: Clockwork will help.Clockwork: I will not help.
- Horrible Judge of Character: Alt!Maddie thought it was a good idea to marry the selfish, ghost-forbidding Vlad Masters instead of sweet, ghost-hunting Jack Fenton. In her defense, Vlad told her Jack didn't want to see her anymore, and grief does make people do desperate things.
- If I Can't Have You...: Vlad must know his manipulations have only succeeded in trapping both him and Maddie in a loveless marriage, but he'd rather see her miserable with him than happy with Jack in another timeline.
- I Just Want to Be Normal:Danny: Just once, I'd like to know what it's like to live in a normal family!
- Irony: Jack thinks Maddie, a ghost hunter, could never accept him now that he's half-ghost. While this is shown not to be true for Maddie in that timeline, it's exactly the same way Danny felt about Valerie in the original timeline, which is why he resolved never to let her know his secret right before they fell apart. Like father, like son.
- It's All About Me:Danny: You don't understand! None of this should be happening!Vlad: You think I care? I like it this way!
- Love Makes You Evil: Even without ghost powers, Vlad's still as determined as a phantom not to let anyone take Maddie from him.
- Never Say "Die"/Getting Crap Past the Radar: Uses the old it's-not-death-if-you-don't-explicitly-100%-confirm-someone-died trick.
- Papa Wolf: "GET AWAY FROM MY SON!" Even when he can't remember being his father, Jack won't let anyone harm his son.
- Poison-and-Cure Gambit: Vlad infects Sam and Tucker with the ecto-acne to ensure Danny will help him find a cure.
- Redemption Quest: Danny's adventure becomes this after he realizes the effects of what he's done.
- Rescue Romance: Deconstructed — Maddie looks smitten after Vlad saves her from the explosion, but it's clear she's miserable in her marriage. Whether she felt obligated to marry him out of gratitude or simply overestimated his character based on that one seemingly-noble act, rescue is not good grounds for romance in this case.
- Set Right What Once Went Wrong: Clockwork has no objection to doing this (fixing problems with the timeline caused by time travel), but he is firmly against Wayback Trips (using time travel to fix problems in the past that were not caused by time travel).
- Temporal Paradox: Time travel continues to work the way it did in The Ultimate Enemy — Danny still exists even though he went back in time and changed events that caused him to never exist in the new timeline.
- Trickster Mentor: Clockwork seemed to have planned out this entire chain of events just to teach Danny a lesson about messing with the timeline...but also indirectly helped with Danny's more urgent matters as well. Seems to be a running thing with him, really.
- Whole Plot Reference: The episode is a more serious take on the plot used in "Father Time!" from Butch Hartman's other show The Fairly Oddparents (the hero goes back in time to fix something, only to erase himself from existence by preventing his parents from ever getting together).
- You Are What You Hate: This is one problem Jack has that Danny, not being a ghost hunter, never did. Deconstructed as what nearly keeps Jack from coming clean to Maddie about how he's a half-ghost.
- You Just Had to Say It: Inverted.Maddie: There's only one place on Earth that knows how to treat ecto-acne!Danny: Please say "hospital," please say "hospital," please say "hospital"... Why couldn't she say "hospital"?