"Old people are boring!" Ben thinks. Every Friday evening he has to go to his grandma's house, where the TV is broken and everything smells of cabbage. Ben would even rather go along to "SDancing Stars", the TV programme about ballroom dancing that his parents are so crazy about. Or simply read the latest issue of his plumber's magazine in peace. But then one evening Ben accidentally finds a box of biscuits full of jewellery and diamonds on Grandma's bookshelf. His grandma, an internationally wanted jewellery thief? Ben can hardly believe it until he catches Grandma in the act and she lets him in on every master thief's greatest dream: the theft of the English crown jewels! Ben embarks on a fast-paced adventure that takes him all the way to the Tower of London.

David Walliams is known in England as a television presenter and comedian. However, he has also written numerous children's books, e.g. about a zombie dentist or terror aunties. Hamburg director Hanna Müller brings the exciting and funny story of Ben and his "gangsta granny" to the stage of Theater Lübeck.