‘Yuck,’ the Professor fumed as he pulled a maggot-infested piece of meat from his drawer and threw it on the floor. He would have put it in the bin, but he knew what the Serpent did in the bin.

‘Urggghh,’ he grunted, resigned to carving instead of writing with chalk. He would have to go through all the Serpent’s rubbish to find the knife, but at least then he wouldn’t have to worry about the chalk being rubbed out. He considered hitting the knock-up to tell the guards it was safe to clean his cell, but he decided he didn’t have time to be interrupted. And he didn’t want to anger the Serpent.

A sudden chill stopped him in his tracks. He realised he was naked. He looked down at his body to check for fresh self-mutilation. No bleeding. Good. He wouldn’t have to go to the hospital. He checked for new scars. Had he just come back from the hospital? He couldn’t tell, there were so many scars, but he couldn’t see any fresh stitches or bandages. He was sure there would be some damage somewhere – the Serpent needed pain for his ritual – but he was confident it was nothing drastic. Not this time.

He didn’t bother looking for new ink, but he did notice that his first tattoo was starting to fade. The Serpent had been little more than a voice in his head when Wensley had walked into the tattoo shop and paid $150 to have the chaos theory equation inked on his forearm in twenty-point Helvetica: xt+1 = kxt (1 – xt). The tattooist didn’t even blink: Robert May’s equation wasn’t even in contention when it came to the weirdest tatts requested by walk-ins.

‘Damn you,’ Wensley said when he realised the pants he had just retrieved from a pile of clothes in a corner of the cell were wet. ‘I have had enough of your games.’ He took them off and went back to the pile. A stub of white rolled out from under from a sodden shirt. ‘Yes. Yes, yes, yes,’ he muttered as he chased it across the cell.

He didn’t care that he was cold, now he had his chalk. Naked, he moved to the wall, relieved to find his equation was still there. For a moment, he’d feared the missing chalk and the Serpent’s new carving meant that the ceasefire was over. A while back, he’d made the mistake of wiping off some of the Serpent’s nonsense, and the Serpent had retaliated by rubbing out all of his work. The Professor had then hidden the chalk, but the Serpent started writing in excrement. Finally, the Professor had placed the chalk in the middle of the cell, as an offering. But the Serpent hadn’t wanted a gift. He’d been in a fury. Instead of using the chalk, he’d eaten it, leaving Wensley with nothing.