Fear in a Handful of Dust by Brian Garfield

A mental patient escapes his institution in search of bloody vengeance

When rain falls on the mental hospital, Calvin Duggai knows it’s time to leave. Institutionalized after he abandoned five men to die in the Mojave Desert, he has spent years planning escape and revenge. For months he has tunneled through the asylum’s bathroom wall, waiting for a night when rain will cover his tracks. As water soaks the grounds of the silent institution, Duggai punches a hole in the stucco wall and creeps out onto the building’s ledge. After a mistimed leap, he limps to the chain link fence with a cracked knee.

As he scales the twelve-foot barbed-wire fence, he ignores the searing pain. The men who sent him away must be punished. Duggai has four doctors to kill.