Ned's parents were planning a trip to New York City but had to cancel it when they heard, from Doogle's parents, that they've been watching a show about the urban legend that alligators live in the sewers. Ned and Newton go there to prove that the rumor is false, mainly trying to "blend in with the locals". But they end up falling into the sewers when they're ready to give up, and also accidentally find the sewer alligators.

Ned had rescued an endangered plant for a science fair entry, but the plant soon starts to grow too much and threatens to take over the world.