Here we see that Phil isn’t just some stoner taking this class for the third time (though he is that, too).
More information on psilocybin:
Video from the same series about LSD:
An outstanding explanation of psychedelics and serotonin here:
Phil and Colin discover a cave, and manage to get Sophia mixed up into a crazy adventure into the unknown.
While on a class trip, two college students discover a secret dimension ruled by ancient philosophers, accidentally getting their teacher’s assistant (and Colin’s crush) possessed along the way. They must become enlightened (or fool everyone into thinking they are) to return back home.