Jack's been gone for a while to spend some time with the Doctor, and Torchwood has got quite a bit more effective as a result. For one, they've redecorated the base, Gwen has taken charge of missions and Ianto gets to ride in the car now.
The Torchwood team are chasing a blowfish-headed alien driving a sports car. Said blowfish proceeds to break into a house and take hostages. After sizing up the team and daring them to attack first, he is unexpectedly shot by Jack, fresh from his trip with the Doctor.
Once they return to the Hub, the team demands to know where Jack disappeared to. He mentions that he's "found his Doctor" but that he came back to be with the team. Gwen is now engaged to Rhys. She fumbles awkwardly around Jack for a bit when she tells him, and he promptly stops flirting with her.
Meanwhile, a guy who calls himself "Captain John Hart" arrives from the future. He loves standing on top of buildings just as much as Jack does. Unlike Jack, however, he also likes throwing people off of them. Also, he's a Time Agent and dated Jack for five years.
John makes a dramatic entrance and calls Jack. They make out, punch each other and reminisce about the past. Turns out they were partners (in every sense) before both left the Time Agency. John needs Torchwood to help him gather a series of Plot Coupon canisters. While searching for the things, Jack asks Ianto out on a date — dinner and a movie. Ianto happily agrees.
Torchwood finds the canisters, but John knocks out Gwen by kissing her with poisoned lipstick, takes out Owen by shooting him, headbutts Tosh and throws Jack off of a building.
With Jack sprawled over a bench with a very painful-looking broken back, John tries to use his new gadgets for his own gain. However, all of Torchwood make it back to the Hub in time to point their guns at him. Also, the previous owner of the canisters has set up a trap, and a bomb latches onto John's DNA. Ianto merrily times the bomb with his trusty stopwatch.
John handcuffs himself to Gwen and threatens to blow her up along with him. Gwen decides to drag him into the rift in order to save the city. However, the team manages to inject John with their own DNA just in time, confusing the bomb and resetting time to the start of the day.
John asks to join Torchwood, but Jack just bids him farewell with a sweet kiss. John has one final message: "I found Gray."
- Affectionate Nickname: John deems Ianto as "Eye Candy" when he learns Ianto has become Jack's new lover.
- Anything That Moves: John Hart is this in spades.John Hart: [looking out the window of the Torchwood van] I think I'm starting to see what he likes about this place: she's beautiful, he's stunning...
Gwen Cooper: Do you ever stop?
John Hart: What? Five minutes to live, and you want me to behave?— Oh, that's gorgeous.
Gwen Cooper: [disgusted] That's a poodle.
John Hart: [savagely] That's nice.
- Chekhov's Gun / Foreshadowing: "I found Gray".
- Drugged Lipstick: A rare male example. John forcibly plants a kiss on Gwen that paralyzes her, and would eventually have shut down her internal organs if she hadn't gotten the antidote.
- Extended Disarming: When Captain John Hart is first brought into Torchwood.[Capt. John Hart hands over two guns and a katana]
Captain Jack Harkness: [holds a hand out, makes "gimme" motion] The rest.
Captain John Hart: Oh, you know me. I'm a two-weapon man.
Gwen Cooper: [scanning] One pistol strapped to each leg, laser knife beneath the left elbow, 17 explosive charges in the lining of his coat.
Captain John Hart: Slipped my mind.
- Foil: John is essentially a mirror for what Jack was like before he met the Doctor and Rose, except more violent and with even fewer scruples about showing sexual interest in people... and animals. John even says that he got the paralyzing poison lipstick trick from Jack.
- HeelFace Revolving Door: John flips from approachable to murderous on a dime. One second, he's schmoozing up Jack, the next, he's chucking him off a multi-story building!
- Kiss-Kiss-Slap: When Jack and John come face to face for the first time they kiss, and then proceed to merrily brawl.
- Mexican Standoff: Jack's fight with John Hart ends with mutually aimed pistols.
- No Name Given: "John" is using an alias like Jack, mainly because he was inspired by him to do so.
- Oh, Crap!: John gives a spectacular one when he realizes that not only did Jack survive the fall, but he's also immortal.
- Ooh, Me Accent's Slipping: Honestly, what is John's meant to be?
- Shout-Out: John in holographic message for Jack. "Help me Obi-Wan Kenobi, you're my only hope!"