He stopped in front of Cell No. 74 and, as he bent down to pick up his penultimate delivery, he noticed a strange smell. Something was off. He thought it was the food – until he looked into the cell.

Jax turned away as soon as he saw the filth on the floor: rotten food, rubbish, soiled clothes, insects dead and alive – fruit flies were buzzing around a pile of faeces. He wanted to grab the trolley and keep going but he couldn’t; he didn’t want to attract attention by denying an inmate dinner.

So he stretched the tray as far away from himself as possible while leaning his head back and holding his nose with his other hand. He fumbled as he tried to push the meal into the slot, which was barely bigger than the package he was trying to deliver. As he released it, he sensed something moving inside the cell.

Jax buckled as soon as he saw the Serpent. Already leaning back to distance himself from the air holes, he went weak at the knees and fell on his arse when he saw all the blood.

Oh no . . .

He didn’t want to look again. He knew what he’d seen. But some primal instinct twisted his neck back round and forced his eyes to focus on the mutilated man. On the Serpent.

Jax heaved a little in his mouth, the sight of the Serpent hacking through his own arm, combined with the stench, making him physically sick.

That image would stay with him forever.

Of course, he’d heard about self-mutilation – apparently it was disturbingly common in all jails – but he had always imagined bruises, burns and shallow razor-blade cuts, not what would soon be an amputation if the Serpent didn’t stop. Completely naked and standing in a pile of filth, he was ringbarking his forearm with what appeared to be a butter knife.

Jax didn’t want to look again. He’d seen enough, too much. But his watering eyes swung back to the car crash that was the Serpent as soon as he’d swallowed.

The look on the Serpent’s face was worse than the blood. Blank. Sawing away, knife now so deep it must have been hitting bone, he was expressionless, blank: eyes dead, mouth closed, not a hint of pain.

Jax looked harder. No, not blank. The Serpent was smiling.

Jax no longer even felt sick. Just scared. He wanted to run. To get up off the floor and go. Screw the meals. Screw the phone.

But something told him he needed to stay.

The Serpent suddenly stopped sawing. And then he turned.

Jax didn’t realise he had stood up again until he became aware he was walking towards the plastic glass. Towards the Serpent. The madman was mesmerising.

Part of Jax wanted desperately to turn away, but another part of him couldn’t. The Serpent seemed to ooze some kind of ominous pheromone that drew Jax in.