Riddling rats, meddlesome bats and six missing ravens! The Dog Detectives are cycling through the busy streets of London when they crash into a new case; the six ravens of the Tower of London are missing. With the help of the rat riddler, the Dog Detectives must solve the riddles and find the ravens, before it s too late! The team search amongst well known landmarks, such as Buckingham Palace, St. Paul s Cathedral, Trafalgar Square and Big Ben. Finally the last raven is found in the only place they forgot...The Tower of London!