Quaid ("Quail" in the short-story) previously worked for an intelligence agency and was tasked with going to Mars to assassinate a political opponent of Earth. His memory of his life as a secret agent and assassin was erased to avoid the political ramifications if it ever got out. The problem was the new memories and life they gave Quaid were too mundane, his new life was unfulfilling, which is why he pined to visit Mars as a menial office worker. Instead of a tracking device in his nose, they implanted a telepathic transmitter in his head, and his former employers can read his very thoughts. Despite being able to subdue and overpower the armed agents who have come for him and go on the run, he realizes that it's only a matter of time before they eventually kill him. Through the transmitter, he bargains with his former boss that he'll give himself up to them if they agree to at least try the memory wipe one more time. If it doesn't work a second time, he'll accept his death.

Considering that they never expected Quaid to come back from such a dangerous mission, and because he was able to successfully pull off such a high profile assignment, they grant him this request.

This time, the agency's psychiatric department conduct a personality-profile test to determine Quaid's ultimate wish fulfillment fantasy. This way, they'll implant this fantasy, whatever it is, into his memory, so that it gives him just enough sense of self-importance that he'll be content with whatever new life they give him, without him remembering that he was really an assassin working for the government and that he had killed a planetary leader.

Quaid's ultimate wish-fulfillment fantasy is this: That as a kid walking down a rustic road and an unfamiliar space vessel from another planetary system lands directly in front of him. No one on Earth sees it but him. The creatures within are small and helpless, like field mice, but their race are highly advanced and planning on invading Earth, and this scouting ship who will give the go-ahead to send their fleet of 10,000 vessels to destroy humanity with their terrible weapons of mass destruction.

But instead of halting the invasion by merely stepping on them and destroying the small scouts, Quaid's fantasy is that as a child, he halts the invasion by showing them kindness and mercy, despite knowing their malicious intentions due to them telepathically communicating it to him.

They have never seen such humane traits displayed by a sentient organism, and in appreciation, they make a covenant with the young boy. They won't invade Earth as long as he lives.

His boss is shocked to find out they had a guy with these kind of subconscious fantasies on the payroll. But they agree to go ahead with the new memory implant. They even plan on putting fake mementos of this fake childhood memory in his conapt (condo-apartment): a faux star map of the creatures home galaxy, a scroll written in their language, unreadable of course, and a magic healing rod they gifted him that eventually ran out of power.

They go back to Rekall, and they put him in under. Before they can implant the new memory, Quaid starts mumbling, "They told me not to tell...that was the agreement...they even gave me a scroll. I have it hidden in my conapt."

The technicians freak out and call in the agency boss. "Something went wrong again."

Through eyes have half shut, Quaid looks to the direction of his boss and continues mumbling, "They gave me a magic invisible destroying rod...That's how I killed that man on Mars you sent me to take out. I have it hidden in my desk along with the Martian maw-worms and dried-up plant life."

The agency boss sighs and realizes now they have to keep him alive no matter what.

alien race