Local schoolteacher Dev Hooper arrives home from work to find his girlfriend, Nellie Thorne, has vanished. But she's not the first Nellie Thorne to disappear. In fact, she's the fifth in 50 years. Enter Jane Pye and Simon Mash: a millennial couple who signed up for a private detective night class on a whim. When they're assigned Dev's case for their coursework, they quickly realise they've bitten off more than they can chew. Armed with just six weeks of notes, matching trench coats, and questionable detective skills, they set out to solve a case that has baffled Kent's police for decades. What links the missing Nellies? And why does everyone keep talking about ghosts!? Is it an open and shut case? Not on your Nellie...