Alex's second attempt to break out of Furnace Penitentiary failed. This time, his punishment will be much worse than before. Because in the hidden, bloodstained laboratories beneath the prison, he will be made into a monster. As the warden pumps something evil into his veins--a sinisterly dark nectar--Alex becomes what he most fears . . . a superhuman minion of Furnace. How can he escape when the darkness is inside him? How can he lead the way to freedom if he is lost to himself?

Alex Sawyer has escaped his underground nightmare to discover the whole world has become a prison, and Alfred Furnace is its master. Monsters rule the streets, leaving nothing but murder in their wake. Those who do not die become slaves to Furnace's reign of cruelty. Alex is a monster too. He is the only one who can stop Furnace but in doing so he could destroy everything. Is he the executed or the executioner? Who will die? All Alex knows is that one way or another, it all ends now.
Execution is an Escape from Furnace book from Alexander Gordon Smith.