In the Buffy the Vampire Slayer episode “Normal Again,” Buffy wakes up in a mental institution. All of the monsters and fighting the undead? It was all in her head, merely part of a delusion she was trapped in for months, while she was really just a normal young woman with a normal life. Of course, the delusion was a delusion orchestrated by her enemies in an effort to defeat her.
For a while, I’ve been thinking this premise would make a great fanfiction, and it would work for fics based on a variety of TV shows, especially for a spy or an action-adventurer.
I’ve thought of it specifically for MacGyver: on some sort of mission, he is knocked unconscious, wakes up in the hospital. After the preliminary letting-him-know-what-happened, someone says, “Your wife has been waiting for you.” Of course, he’s all, “My wha…?” They proceed to fill in all the details of his so-called Real Life, but – as with Buffy – it’s just a ruse by his enemies to try to trick him into revealing some information.