Diana Bakewell is London''s savviest and best connected tour guide. As the lead guide at Chartwell and Crouch Tours, she''s busy teaching her young assistant Zaf the ropes alongside dealing with company politics and her slimy boss. In her spare time she''s helping Zaf find his feet in London and coming to terms with the fact that a tabby cat called Gus has stowed away on her vintage tour bus. But when Diana and Zaf take a group of students on a tour of the Houses of Parliament and an MP''s researcher dies, Diana suspects all is not as it seems. The police are at a loss. They interview witnesses, including Diana''s tour group, but seem to be getting nowhere. Diana, however, was at the scene. She witnessed people''s reactions when the young woman died and knows that there''s a link between her group and the murder. Can Diana solve the crime and ensure justice is done, while keeping her tour group under control around London and protecting Chartwell and Crouch Tours'' reputation?