The play begins with a tempest and a shipwreck near an enchanted island. On the ship are Alonso, King of Naples, his son Ferdinand, Antonio, Duke of Milan, and their court. The tempest was actually raised by Prospero, a magican who lives on the island with his daughter Miranda. He explains to her that he was the rightful Duke of Milan; because of his devotion to the State, his brother Antonio deposed him twelve years earlier and set him adrift with Miranda on a boat. They finally reached an island which had been the refuge of Ariel, a spirit the witch Sycorax had imprisoned in the trunk of a tree. Prospero released Ariel and made him his agent.
King Alonso is desperate because he thinks his son drowned. Ferdinand instead wanders through the island, moved by Ariel's singing, meets Miranda and falls in love with her.
To test Ferdinand, Prospero makes him perform menial tasks. Caliban meets Trinculo, the king's jester, and Stephano, the royal butler, and they plan to kill Prospero.
It is a sort of interlude to entertain Miranda and Ferdinand while Prospero readies his plans to reward his friends and punish his enemies.
The play ends in an atmosphere of general reconciliation: Miranda and Ferdinand marry, Prospero forgives his brother and return to Milan to take possession of his lost dukedom. Caliban is left alone on the island and Ariel is relased, free to wander as he wishes.
The Tempest belongs to the last period of Shakespeare's work and it is characterized by a "serenity" which casts sweetness and light over human relation. Shakespeare seems much more concerned with human destiny as a whole rather than with individual peculiarities, more eager to show that good may come of evil. There is, in fact, no tragic ending: not only are criminals prevented from causing death, but they are also forgiven. Forgiveness seems to be one of main themes: all ends in peace and reconciliation, with music intensifying the atmosphere of enchantment. Miranda is not a suffering heroine, she embodies womanly perfection through her ethereal beauty and unspoilt innocence. There is another element in the play that was certainly of greats interest for a Jacobean audience: the wild, exotic setting, the relationship between natives and invaders, the problem of forced labour and the traffic in liquor. However, the most interesting theme of the plays is certainly the "element of magic" and its representation as "theatrical illusion". There are two types of magic in the play, maleficent and beneficent. The former, used by the witch Sycorax, tends to work evil on its victims and is usually the result of a pact with the devil. The latter, employed by Prospero, derives from study and is used only for good purposes. Prospero's magic accessories represent his supernatural knowledge; his robe, which he puts on when he is working as a magician and takes off when he is an ordinary man; his wand, which represents his instrument of power.