-After becoming depressed about his 40th birthday, Jeff takes some "youth pills" with a bottle of whiskey, and promptly falls into a coma.
-While in the coma, Jeff imagines himself and the study hall gang as characters in the G.I. Joe universe--alongside real G.I. Joe characters.
-After Jeff accidentally kills Destro-- committing the first murder in the history of the G.I. Joe world--he and the gang become outlaws.
-Jeff flashes back to his Greendale reality in bits and pieces, but once the truth has been revealed, Jeff announces that he intends to stay in the G.I. Joe universe forever--instead of coming out of his coma and living life as a man in his forties.
-However, an encounter with the combined forces of G.I. Jobra shows him the many perks of adulthood that don't exist in the G.I. Joe universe--such as scotch, and boobs.
-Jeff forces his way back to consciousness, and accepts the reality of aging.