Even the best of men are punished for their good intentions. Witness the murder of eight-year-old Elliott's mother and his father's brutal execution of the killer, which lands him in prison, and the malevolent consciousness approaching on the tail of a comet. Leon Weber is in the final month of his sentence; he's about to go home to his son, but a violent storm destroys Wormwood Scrubs, releasing him into a world overrun by an alien menace, not the usual burn 'em down aliens, but the fungal spores of a mossy plant with conscious thought and malicious intent: to consume every living thing on earth. Elliot and a band of survivors are kidnapped for later consumption by an alien mind more resourceful than any human's. Leon's journey to find his son is fraught with danger and death, but the future of the world rides on his meager leadership skills...and an ill-tempered redhead.