London, as you've never seen it before!

Meet Diana Bakewell, London's best connected tour guide. She's the most experienced guide at Chartwell and Crouch Tours, where she's recently been joined by Zaf Williams and is soon to be joined by Gus the cat. Alongside them is Newton Crombie, who drives the vintage Routemaster bus.

Zaf has dropped out of university after leaving Birmingham and his big sister DC Connie Williams (from Zoe Finch's team). Disillusioned by his experiences in the city, he was about to go home when Diana suggested he might like to come and work with her.

But their work proves to be far from straightforward.

As they accompany tour groups around London, they find themselves at the centre of a series of murder mysteries. The suspects are often people accompanying them on the tours. Can they solve the mysteries and keep Chartwell and Crouch safe from the machinations of their incompetent boss?