Oh, what a tangled web we weave, when first we practise to deceive...

For the first time since her engagement came to an unhappy end, catering manager and amateur sleuth Sophie Lockwood returns to London from Derbyshire to run the café for an art exhibition hosted by her employers, the Duke and Duchess of Ravensbury, in their splendid city home. On her first evening in the capital, while Sophie is listening to renowned botanist Dr Ambrose Pitkin praising the artwork of the Duke's ancestor, a lethally sharp souvenir letter opener falls into the possession of someone with murder, not mail, on their mind.

When Dr Pitkin is found the next morning stabbed to death in Green Park, Sophie is determined to see justice prevail, but it seems as though everyone who visited the Duke and Duchess the previous night had reason to want him out of the way. With so many questions to answer and a hostile detective inspector to deal with, Sophie wonders if this will be the first case to defeat her. And in the midst of her confusion, the last thing she needs is ex-fiancé Adam back on the scene.

A moment of enlightenment over coffee with one of Dr Pitkin's colleagues at the Natural History Museum leads Sophie to the truth. And it's a truth that will have devastating consequences not only for her personally, but also for her noble employers.

Mystery fans, grab your snacks and board the train. We're heading to the capital...