A very strange conversation now takes place. What is Stephano calculating? What is Caliban begging for? What happens when Trinculo joins? How is the mystery resolved?

Caliban sees Trinculo and imagines him to be one of the spirits. Hoping to avoid pinching, he lies down and covers himself with his cloak. Trinculo hears the thunder and looks about for some cover from the storm. The only thing he sees is the cloak-covered Caliban on the ground. He is not so much repulsed by Caliban as curious. He cannot decide whether Caliban is a “man or a fish” (II.ii.24). He thinks of a time when he traveled to England and witnessed freak-shows there. Caliban, he thinks, would bring him a lot of money in England. Thunder sounds again and Trinculo decides that the best shelter in sight is beneath Caliban’s cloak, and so he joins the man-monster there.

Check out the link, it is all there.

You need to read the entire scene here............

Caliban begs Stephano not to torment him.

Stephano on the other hand, is calculating the monster as having four legs and two heads.

Stephano is then joined by Trinculo who crawls out from under Caliban where he's been seeking shelter. (This is how the mystery is resolved).