Three men – one fat, one tall, one thin – meet on the outskirts of London to hatch a plan to steal the wealth of a nation.

They have no regard for the chaos and horror that will be unleashed in the process. Their plan is put into action, and the death toll rises and rises.It is up to Department Z’s Gordon Craigie to put a stop to these powerful and ruthless men. His only clue is a mysterious diamond-shaped card. It is on this small lead that the fate of Department Z hinges. But, with the life of his top agent Toby Arran on the line, is this one clue enough?

Days of Danger is the ninth book in the Department Z series, and was originally published in 1937.