The SGC receive a phone call from a conspiracy theorist named Martin Lloyd, who claims to have information about the stargate; furthermore, upon meeting with O'Neill, he insists that he himself is an alien. O'Neill is initially dismissive of Martin's claims, but comes to realize there may be more to his story when Carter and Daniel are abducted by a group of shadowy individuals somehow involved with Martin.
"Point of No Return" provides examples of the following tropes:
- Abandoned Warehouse: Dr. Tanner lures Daniel and Carter to one in order to take them hostage
- The Bait: O'Neill and Teal'c use Martin as bait, putting a GPS tracker on him and following him to where Carter and Daniel are being held when the others come to take him away. Martin is less than thrilled by this.
- Bound and Gagged: Carter and Daniel end up zip-tied to chairs while they're being interrogated by Tanner's men.
- Cassandra Truth: Despite his having accurate knowledge of the stargate, O'Neill doesn't take Martin's claims that he's an alien particularly seriously until they find his spaceship.
- Come Alone: Martin instructs O'Neill to meet him alone in the message he leaves for the SGC at the beginning of the episode.
- Conspiracy Theorist: Martin is something of a Deconstruction, since not only do most of his claims turn out to be correct, but the reason he knows the truth is that he himself is an alien.
- The Cuckoolander Was Right: Since Martin has the demeanor of a Strawman conspiracy theorist who happens to be taking a whole pharmacy's worth of different psychiatric medications, the team initially write him off as a harmless nutjob who stumbled upon some information about the stargate program, only for it to turn out that he really is an alien and he really is being watched by a shady organization who altered his memories. He's only wrong in thinking that the government was responsible, when in fact it's his fellow aliens.
- Escape Pod: It's revealed that Martin and his comrades crash-landed to earth in one of these after deserting their military in the war that destroyed their homeworld.
- Foreshadowing: When Martin first tells O'Neill what he knows of the stargate, O'Neill responds that it "sounds like a good idea for a TV show." The following season, Martin would go on to make that very show.
- Hypocritical Humor: Tons of it.Martin: You still don't believe me? I'm an alien!O'Neill: You look pretty human to me.Martin: What I believe is that thousands of years ago, people were taken from Earth. Maybe as part of some experiment, maybe as slaves, who knows? But the point is, there are entire civilizations up there descended from those original humans.O'Neill: Now that's just crazy talk.
- Inhumanable Alien Rights: Discussed:Martin: This is totally unfair. Just 'cause I'm from another planet, I don't have rights? I mean, doesn't the Geneva Convention cover extraterrestrials? I have to remember to go online and look that up.
- Klingons Love Shakespeare: Teal'c seems to enjoy the vibrating beds in the motel that he and O'Neill stay at a little too much.
- Last-Second Word Swap: O'Neill does this as he's preparing to ditch Martin, only to get a note telling him to stall so that the others can search his house.O'Neill: Look, Marty, I'm a busy man, and you don't strike me as any great threat to national security... [looks at the note, which reads "WE'VE GOT HIS ADDRESS STALL HIM."] ...but as you know, it never hurts to be thorough.
- Locked in the Bathroom: Teal'c locks Martin in the motel bathroom and refuses to let him out when he becomes overly insistent in demanding his medication.
- Long List: Martin rattles off a long, long list of conspiracy theories in his initial message for O'Neill at the beginning of the episode.Martin: [on recording] I know all about Roswell, and the Kennedy cover-ups, and the...Hammond: [fast-forwarding the tape] He goes on like that for quite a while.Martin: [on recording] ...and the CIA-sanctioned microwave harassment, and the...Hammond: [fast-forwarding some more] Quite a while.Martin: [on recording] ...and the lizard people!
- The Men in Black: Tanner and his men invoke this, though they don't actually work for the government.
- Moon-Landing Hoax: Yet another one of Martin's beliefs.Martin: For the longest time I was obsessed with all those alien conspiracies. Crop circles, cow mutilations, the Apollo cover-up.
O'Neill: I thought the lunar landings were a hoax.
Martin: (surprised) No! That was a story created by the government to direct attention from the real cover-up. Everybody knows that!
- Oh, Crap!: When Martin realizes that the device he stole from Tanner is displaying a countdown.
- Overt Rendezvous: O'Neill meets Martin in a diner at the beginning of the episode.
- Properly Paranoid: Martin. Nearly all of his "delusions" wind up being true, even if not in the exact sense that he expected.
- Psycho Psychologist: Dr. Tanner poses as a psychiatrist and gives Martin "medication" that alters his memory in order to convince him — and everybody else — that he's crazy.
- Running Gag: O'Neill tells Martin that the stargate program is really to do with "magnets".
- Self-Destruct Mechanism: Tanner sets the self-destruct on the escape pod in order to destroy the evidence of their true identities.
- The Stakeout: Carter and Daniel stakeout O'Neill's initial meeting with Martin, complete with surveillance van. This is lampshaded, naturally.Daniel: You know, I've never been on a stakeout before. Shouldn't we have, like, donuts or something?
- They Would Cut You Up: Martin fears that this is what would happen if the government were to find out that he's an alien.
- To the Pain: As he's preparing to interrogate Carter and Daniel, Tanner begins pulling a series of increasingly lethal-looking torture implements from his bag.Tanner: I understand your reluctance to cooperate. Situations like this, information is on a need-to-know basis. Fact of the matter is, we're running out of time, I'm running out patience, and I really need to know.
- Where's the Kaboom?: After Martin notices that the device he stole from Tanner is counting down, everybody assumes there's a bomb in the facility and makes their dramatic escape. When nothing happens, there's a few seconds of awkward silence and it's revealed the countdown was actually for the self-destruct of Martin's escape pod, several miles away.
- You Can't Go Home Again: It turns out that Martin's homeworld has been pretty much completely destroyed after his people lost their war with the Goa'uld, forcing him to remain on Earth.