Naturally Tripitaka gets captured by them, as do Pigsy and Sandy who prove to be as useless as ever - especially Pigsy, who doesn't even put up a fight when he is caught in a honey trap by the lady Silver Horn. So it's up to Monkey to rescue them.
Most of the action centres around the demons' magic gourd that can trap and kill people. Monkey, learning of its existence and properties, fakes up a magic gourd of his own that can supposedly 'swallow the universe' (hence the episode title) and swaps it for the genuine magic gourd with a pair of gullible henchmen.
There follows various shenanigans - Monkey is briefly caught in the gourd but gets out and pretends to be his own brother. He fights with the demons and eventually Golden Horn is caught in his own gourd and killed by it. His wife is distraught by this and so Monkey and the others get away.
This is a decent enough episode, well-realised (by Monkey's standards anyway - only a couple of really dodgy effects) and the simple plot is well padded, with Monkey being captured by Silver Horn three times: once with the gourd, once under a mountain (Monkey escapes easily; it's not the first mountain he's been trapped by), and once with a magic rope.
This last is the cause of the best line of the episode - the Narrator says: "When what is indestructible meets what is irresistible, the female all too often wins. Monkey has been roped by a lady."