If thou more murmur’st, I will rend an oak
And peg thee in his knotty entrails till
Thou hast howl’d away twelve winters.
So there’s a shipwreck. Then the scene shifts to Prospero’s island, which he occupies with the young Miranda, his daughter. Also on site are Ariel, who appears to be some kind of a shapeshifter, and Caliban, the mutant son of the wicked witch Sycorax. And, of course there's Gilligan and the Skipper too.
Turns out – as least as he tells it – that Prospero and Miranda ended up there after some political intrigue found them put to sea on a decidedly not seaworthy vessel, which wrecked on the island. Turnabout being fair play, it seems some of those who schemed against him also found themselves at sea and that the shipwreck that opens the play was conjured up by Prospero and Ariel, who have wizardy Harry Potter type powers.
All of which is quite fine stuff, actually, especially after the relative tedium of the Henry IV plays.