He heard footsteps. He lay still until he was sure they were approaching, then began to feel around for a weapon. As Eliot saw it, there were two plausible scenarios. In one, Wil had driven away with the bareword, as Eliot had instructed, and the footsteps belonged to someone from the organization, coming to kill him. In the other, they belonged to Wil, who had been too cowardly to leave, and instead hung around hoping Eliot would wake up and tell him what to do. Either way, Eliot felt the need to shoot someone.
