The shiny silver button that closes Tower Bridge is missing! Bella the Tower Bridge Cat needs to find it in time for the Lord Mayor's Show to start. But Bella soon discovers that there are buttons going missing all over Tower Bridge. Buttons are missing on a pair of trousers, on remote controls, and even on the gingerbread men! What is happening? Bella must look high and low to find the missing buttons. But with so many places to search, can the Tower Bridge Cat solve the mystery of the Missing Button in time?