Mr. Lies
Harper Amaty Pitt's imaginary friend. He is a travel agent who sold Joe and Harper their plane tickets to Brooklyn, NY. In Harper's mind, Mr. Lies is able to take her away from her problems and shield her from the reality of life. She summons him whenever she wants to escape her present surroundings, though Mr. Lies cautions her that there is a limit to her ability to flee from reality.
There is an underlying conflict between what Mr. Lies is telling Harper, and what the Angel is telling Prior Walter. The Angel is saying that progress and moving foward has removed us from God and, if we continue along this path, distruction will come. In contrast to that Mr. Lies says "It's the price of rootlessness. Motion sickness. The only cure: to keep moving." This statement makes us question Mr. Lies true agenda. What Mr. Lies is telling Harper is very interesting because in the Bible Satan is referred to as the Father of Lies. If Mr. Lies is an incarnation of the Devil then he would know that God had left. He would be trying to keep as many people as possible moving and progressing.