Sarah had never committed a single blunder. True, she had been finding it harder to concentrate since beginning her treatment, she was less focused, she forgot the odd detail, a name, or a term that had been used in conversation, but never in any way that had affected the quality of her work. She never missed a meeting with a client or colleagues. She felt weak and shrunken inside, but she tried harder still to make sure nothing showed. She had committed no blunders or mistakes, as Inès knew full well.

So why? Why betray her? Sarah understood too late, and the thought made her blood run cold. Inès wanted to take her place. She wanted to make partner. There were few chances of promotion in the firm. Juniors were seldom bumped up the ranks. A weakened partner was a door left ajar, an opportunity not to be missed.

Curst was serving his own interests, too. He had always envied Sarah’s close, trusting relationship with Johnson. She was clearly his next-in-line for Managing Partner. Unless something – or someone – blocked her rise … He, Gary Curst, pictured himself in that seat, at the top of the pile. A long illness, as people said. A vicious, pernicious disease that attacked you, weakened you, a disease that could come and go, the ideal murder weapon, a fatal blow to an old enemy. Curst would come through it all spotless, with not a drop of blood on his hands. The perfect crime. Like a game of chess. A pawn falls; everyone moves one square forward. And the pawn was Sarah.

One word was all that was needed. One little word in a receptive ear and the damage was done.

It was official now, everyone knew: Sarah Cohen was sick.

Sick – which meant vulnerable, fragile, likely to drop out in the middle of a case, to fail to see a piece of work through to the end, to take extended leave.

‘Sick’ meant unreliable, not to be counted upon. Worse, someone who might leave forever in a month, or a year. You never know. Sarah heard the dreaded phrase, barely whispered, in the corridor one day: you never know.

Sick was worse than pregnant. At least you knew when a pregnancy would end. Cancer was sneaky, you might enter a period of remission, but then it might come back. It was there, like the sword of Damocles over your head, a black cloud that followed you wherever you went.