Still waters run deep in this baffling new case for the Charity Shop Detective Agency!

Wild swimming in February? No, thank you . . .

To Fiona, Daisy and Partial Sue, the retired ladies behind the counter at Dogs Need Nice Homes charity shop, it sounds like torture.

Still, no one ever died of plunging themselves into the icy sea waters. Until now.

When the body of Colin Barclay — retired PE master and wild-swimming fanatic — washes up in a secluded cove, the ladies begin to realize just how dicey this wellbeing trend can be.

Especially when a shifty new customer comes calling at their charity shop.

Is this where you solve murders? She asks, her eyes darting wildly round the shelves of bric-a-brac. I think I have one . . .

This woman knows Colin better than most. And she’s convinced his death was no accident. It was murder.

But she’ll need the ladies to dive in and help her prove it . . .