Monsters

Monsters is a dystopian novel set against the backdrop of the collapse of civilization. The fallout from a passing comet contains a biological pathogen, not a virus or a living organism, just a collection of amino acids, but these cause animals to revert to the age of the mega-fauna, when monsters roamed Earth.  
Bruce Dobson is a reader. With the fall of civilization, reading has become outlawed. Superstitions prevail, and readers are persecuted like the witches and wizards of old. Bruce and his son James seek to overturn the prejudices of their day and restore the scientific knowledge central to their survival, but monsters lurk in the dark.