163a - Mermaid Man Begins
The episode begins at SpongeBob's house, and SpongeBob and Patrick are preparing for a Mermaid Man and Barnacle Boy television marathon. As the first show, an "Origin Special," begins, SpongeBob's house loses power and then a wind rips the house and TV away. SpongeBob and Patrick go to Squidward's house, but the wind follows them there and destroys his house, too. SpongeBob and Patrick go to the Mermalair to ask the heroes about their origin in person.
Mermaid Man goes on a flashback, but it wasn't the actual story of his origin. Then, he tells another flashback, this time it is the origin story. In this flashback, Mermaid Man encounters mermaids while he is drowning that let him breathe underwater with the sea star on his nose.
Then, Mermaid Man tells a flashback where he finds a drowning Barnacle Boy and saves him. They then become partners, partly because Barnacle Boy was stuck breathing underwater for the rest of his life as a result of the rescue. They stop a bank robber in the next flashback, then thwart Man Ray in the next, but the two argue over the legitimacy of the flashbacks.
Then, the "actual" origin episode starts to air on the Mermalair's giant monitor, in which Mermaid Man (called Ernie in the story) and Barnacle Boy (called Tim in the story) are roommates. The following "origin episode" didn't make sense because of how random it was (see transcript for details). After cooking popcorn for movie night, they are thrust into an improbable series of events, and eventually return to their apartment. The now overcooked popcorn causes a radioactive effect on the two, giving them superpowers and the urge to fight crime underwater. They dive into the sea and start fighting crime. As the show ends, Mermaid Man and Barnacle Boy were baffled. Finally, the camera cuts to SpongeBob and Patrick putting popcorn into a microwave with intent to overcook it and give themselves powers. The episode then ends with Mermaid Man and Barnacle Boy yelling "No! Stop!"