George R.R. Martin's Doorways #4
Trapped in a reality where oil doesn't exist. Chased by murderous gangs AND inhuman manhounds. An impossible distance to cover before reaching the next Doorway in time.
Tom and Cat have come a long way since they first met, but things just keep getting worse. With no friends and alone in a strange world, Tom and Cat have no one to rely on but themselves. The stakes have never been higher than in this concluding chapter!