After travelling through time and space with the Doctor, Henry Gordon Jago and Professor Litefoot are back in London starting brand new lives. Jago has become a huge celebrity and Litefoot the quiet owner of a bookshop, but in all other respects it is business as usual.

As they investigate a wealth of new cases – including a restaurant where the food eats the people, and a book with dangerous powers – a long game is playing out. A figure from their past is back, and this time he means to destroy them...