Autumn has arrived, with crisp, cold mornings, dew on the grass and hedgerows full of blackberries...

When budding garden sleuth Poppy is invited to a party in a beautiful orangery, the last thing she expects is to witness a lethal wasp attack! As authorities investigate the possibility of murder, Poppy is horrified when local handyman Joe Fabbri, her friend and mentor, becomes the main suspect. Determined to prove Joe's innocence, Poppy sets out to solve the case - with help from her "mad scientist" neighbour, his new robotic invention, and a particularly stinky mushroom!

Meanwhile, Poppy is also learning that gardening isn't just sunshine and roses. As she grapples with wind, rain, and unpleasant autumn chores, she wonders if she's bitten off more than she can chew. With limited horticultural experience and a long winter ahead, can she really make a success of the cottage garden nursery that she's inherited?

As Oren, the talkative ginger cat, lends a paw, and crime author Nick Forrest helps her dig for clues, Poppy makes a startling discovery: could there be a link between the murder victim and her long-lost father? Would solving this case also give her answers to the biggest mystery from her past?