Heather McComber is the granddaughter of Marc McComber and a former member of The Order. She is a bit of a mysterious figure since there is very little concrete, empirical information on her personally. On the other hand, quite a bit is known about her family. She first appeared in Log #Entry 20.
Heather is the owner of an odd chest passed down through the McComber family as an heirloom. Heather first appears in the series when Chris notices the chest at her yard sale, recognizing the symbol on its side as the iconic symbol of The Order. Chris tries to buy the chest from her, but she claims that the chest is a "McComber family heirloom". Recognizing the name McComber, Chris, pretending to be a history major doing a video project on "cultural artifacts", asks her if he can interview her about the chest.
Chris, along with his friends, Alex and Jesse, later devise a way to steal the contents of the chest, which ultimately proves successful. When The Order later steals the contents of the chest from Chris, Heather is told the truth about what occurred. Sympathetic to Chris, given his condition, she decides not to press charges. Instead, she invites the two into her home again and explains that she has not been entirely truthful with them, either. She admits that her father and grandfather are both members of a "secret society"; it is no stretch of the imagination to assume they are members of The Order.
Heather later reveals her status as a member of The Order to Chris and Alex, warning them of the coming "harvest" and asking for their help, only to be turned down. Days later, Chris confronts her, believing her to be responsible for The Order killing his and Alex's families. As she claims otherwise, a member of The Order in a red executioner's mask appears and attempts to kill Heather, shooting her in the leg as she flees with Chris.
After recovering, she stays at Matt Sharky's house to hide from The Order along with Chris and Alex until they learn of his betrayal and kill him.