Merlin's Secret

Augustus, an old country mouse, arrives in London from the West Country with a mission. Merlin, the ancient sorcerer, wants his help to pass a secret to the human who lives at Buckingham Palace. It is the secret of good kingship - a great honour for the mouse chosen to deliver it.
When he reaches the London Underground, Augustus asks the local mice to assist, but they are not street mice and do not know the way. Drury, an escapee from The Royal Opera House, is asked to help . . . or else! Drury doesn't have a clue but he wants to get back home so he agrees.
On the way, the mice get lost, use the wrong address, find the wrong person and must deal with Kaiser, a feral cat and scourge of the Underground. With problems like this, Augustus's faith in Merlin is stretched to the limit.