THIS INMATE USED HIS SOLITARY CONFINEMENT TO LEARN MATHS. NOW HE’S SOLVING THE WORLD’S HARDEST EQUATIONS.

THE WALLS OF THE CELL WHERE CHRISTOPHER HAVENS WAS SERVING A 25-YEAR MURDER SENTENCE WERE COVERED IN NOTEBOOK PAPER.

The sheets filled with numeric and Greek scratchings had quickly overwhelmed his modest desk and were now forming a patchwork wallpaper that spread from that corner and began to wrap around the 2.4 × 3.6 m room. The neatly nesting equations of the continued fractions guiding his chase could run on for 4.5 m as he hunted for patterns that might offer a clue.

Some pages were complete nonsense, grasps into the unknown with whatever method appeared to him. Other pages made progress. They showed promise in his self-taught number theory education. Though Havens didn’t know this yet. He also didn’t know his problem didn’t have an answer.

Guards and other inmates would do double-takes as they passed. He looked like a freak, but that didn’t matter anymore. He was getting somewhere. He was leaning into sticking out. Fitting in had gotten him into prison in the first place.

NOVEMBER 2012 WAS NOT THE FIRST TIME CHRISTOPHER HAVENS WAS sure he’d hit rock bottom. There were the years he spent on the run from the law, when his family assumed he was dead. There were nights spent shivering on the streets of San Francisco and losing custody of – and contact with – several of his children. Like most addicts, Havens had splatted on to what he swore would be the very last bottom he’d ever hit more than once. But this had to be it.

Havens was in a solitary confinement cell at the Washington State Penitentiary in Walla Walla, Washington. When he’d arrived at the high-security facility to serve 25 years for murder, he’d felt fitting in was his best chance at not ending up a target. ‘During a phone call from prison, my father asked me if I was going to be a clown fish in a sea of sharks,’ he says. Havens chose to be a shark. He began ‘probating’ for a gang – like pledging a fraternity. One