Sitting, numb, on his sofa, Roz’s arms wrapped around him, he’d half-listened while the veteran copper gently broke the news to him. Katie, taken ill in a club at one in the morning; 999, ambulance to hospital, her condition deteriorating by the minute. Hallucinating and convulsing. Frothing at the mouth. Dead on arrival. Nothing anyone could have done for her, in the opinion of the medics. His sister had been a walking corpse from the minute she dropped the second pill.

Reading the medical report later, the cause of death was all too clear. Katie, out clubbing with new friends, had gone along with a group decision to experiment with some old-school entertainment. And taken what they had believed to be ecstasy, a blast from the past.

But what the dealer – now deceased Warren – had sold the group, by mistake, was something quite different. Ecstasy, MDMA, being a relatively harmless recreational drug, if made carefully. Not risk-free, not by a long chalk. But tame compared to PMA. Which was what Warren had fished out of his pocket by mistake. Para-Methoxyamphetamine. Street name: Doctor Death. An antidepressant, but with a psychedelic edge. And not a drug to take liberties with.

All the young women had taken one. Only Katie, finding it lacking the usual euphoric effect, had taken a second tablet. Having already snorted two lines of coke an hour before. Expecting it to put her on the ceiling for the rest of the night. Instead of which the stronger dose, lethally combined with the coke, had killed her in under an hour.

In the early days, coping with the arrangements for parents too torn up to manage, Mickey had avoided brooding. Encouraged by Roz to put it behind him and move on. Perhaps because she knew, deep inside, what he was capable of. That, and the funeral itself, obviously, had emotionally flattened him for the best part of a month. Doing his job professionally but seeing everything through a grey filter.

Until he’d met Martin for a drink a few weeks later. Martin, who, having practically lived at Mickey’s during their teens, was equally bereft at her loss. And, in the course of spilling their guts, the idea of killing Warren had sprung to mind.

Whose idea had it been? Neither of them was very clear, once the hangovers had dispersed.

Was it feasible? Of that, there had never been any doubt.

Was Mickey really going to see it through? In spite of the professional and personal risks of losing everything?

That was never in doubt either. Especially once Nemesis took a hand.

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