Burnt — Anthony Horowitz

Uncle Nigel is determined to get a sun tan. But Tim is sure there is something sinister going on, when his uncle's skin starts to frazzle and his brain begins to fry.
When Bart buys a magical monkey's ear in a market in Marrakesh, he discovers that making wishes is a dangerous game - you might just get what you wish for . . .
And who is the writer of the shortest horror story ever written?