When Ava and Luke discover a mysterious box of papers in their attic they are instantly curious about secrets it might hold. As they read through letters, diary entries, newspaper cuttings and listen to secret recordings, they realize that a decades-old, still unsolved, murder mystery is unfoldign right in front of them . .  .

Ava and Luke decide to try and crack the case themselves. But as they work through the clues, it soon becomes clear that the mystery isn't something left in the past: the killer is still out there -  and might be closer than they think...