List of characters in the Camp Half-Blood series
Janus - The God of Gates, Doorways, Beginnings and Endings. He appears as a minor character in The Battle of the Labyrinth where he offers Annabeth a choice between two doors, which represents the situation she was in when she had to make the decision about saving Luke's soul. He has two faces, and each face seems to think the exact opposite of what the other face thinks. He is also mentioned when Percy Jackson has a dream of Deadalus. Janus makes him choose to become a murderer, which he must bear a burden for as long as he lives.