Len Cordova

Claire has overdone it in Halloweens past and the neighbors definitely don't share her enthusiasm, so this year she's being forced to tone it down and keep it "kid-friendly," and Phil has an idea to hold an open house on Halloween night. Meanwhile, Mitch and Cam host a costume party while contending with Lily wondering who her real mom is, and Gloria's pregnancy hormones are on overdrive, making her even more hotheaded than usual.

The alibi of an abducted girl's father clears him of suspicion, leaving the profilers to search her seemingly safe neighborhood for the person who is responsible.

Aiden and Emily discover long-buried family secrets; Victoria pays Mason Treadwell (Roger Bart) a surprise visit as she gets closer to exposing Emily.

Jack and Sayid devise a plan to confront the Others and get Walt back; Eko and Locke fight over the decision about the button and the hatch.