"Ten years ago, Theodora "Teddy" Angstrom's older sister, Angie, disappeared. Her case remains unsolved. Now--on the anniversary of Angie's disappearance--Teddy's father, Mark, has killed himself. Unbeknownst to Mark's family, he had been actively investigating conspiracy theories sourced from a Reddit community of true crime fans fixated on Angie, and Teddy soon finds herself falling down that same rabbit hole. After all, if hope dies last, Angie...