Sir Toby, Sir Andrew, and Maria plan revenge on Malvolio. They convince Malvolio that Olivia is secretly in love with him by planting a love letter, written by Maria in Olivia's handwriting. It asks Malvolio to wear yellow stockings cross-gartered—a colour and fashion that Olivia actually hates—to be rude to the rest of the servants, and to smile constantly in the presence of Olivia. Malvolio finds the letter and reacts in surprised delight. He starts acting out the contents of the letter to show Olivia his positive response. Olivia is shocked by the changes in Malvolio and agreeing that he seems mad, leaves him to be cared for by his tormentors. Pretending that Malvolio is insane, they lock him up in a dark chamber. Feste visits him to mock his insanity, both disguised as a priest and as himself.