A locked room. A mysterious death. Just another gig for the Dizzy Heights.

When London's finest jazz musicians, the Dizzy Heights, are booked to play the glitzy Midsummer Ball at a country house in Oxfordshire, they expect a weekend filled with flappers and toffs having a roaring good time.

But the festivities at Bilverton House take a turn for the worse when the group are stranded by a summer storm. And when a member of the Bilverton family turns up dead in a locked room in an apparent suicide, Skins, Dunn and Ellie realise this is going to be a much tougher gig than they thought.

But here's the lick. What if it was in fact cold-blooded murder? And what if the killer is still at large? It's up to the Dizzy Heights to once again put down their instruments and get improvising if they want to solve this confounding mystery.