Tippy Chan is eleven and lives in a small town in a very quiet part of the world - the place her Uncle Pike escaped from the first chance he got as a teenager. Now Pike is back with his new boyfriend Devon to look after Tippy while her mum's on a cruise.
Tippy is in love with her uncle's old Nancy Drew books, especially the early ones where Nancy was sixteen and did whatever she wanted. She wants to be Nancy and is desperate to solve a real mystery. When her teacher's body is found beside Riverstone's only traffic light, Tippy's moment has arrived. She and her minders form The Nancys, a secret amateur detective club.
But what starts as a bonding and sightseeing adventure quickly morphs into something far more dangerous. A wrongful arrest, a close call with the murderer, and an intervention from Tippy's mum all conspire against The Nancys. But regardless of their own safety, and despite the constant distraction of questionable fashion choices in the town that style forgot, The Nancys know only they can stop the killer from striking again.