Summary

In “Sadie,” Sadie is unable to sleep because she keeps thinking about Morgan’s six-year-old stepdaughter finding her mother dead. From that, Sadie's thoughts move to whether the killer is still on the island with them or if he has left. She gets up and checks the children. Tate is in bed asleep. At first, she fears she will discover Otto has snuck out, but he is in bed asleep as well. She goes to Imogen’s room, but the door is locked from the inside.

Downstairs, Sadie lets the dogs out. She notices they go to one particular spot in the yard and begin digging, their new obsession. She picks up a book Will has been reading and is surprised when a picture of Erin, Will’s first fiancée, falls out. She wonders why he still has the picture.

Will had...