His left hand, palm upwards on the exam bed, twitched a bit as he tried to control his temper. Paula pictured his hands encircling Rochelle’s slender neck, mashing her larynx, crushing the blood vessels to frayed threads, squeezing the oxygen out of her.

Should Paula confront him? Call the police right now? They wouldn’t arrest the guy just for making menacing boasts about tracking down his wife. Paula had no proof. Rochelle would be too afraid to speak openly. And if Paula called in the authorities, Rochelle would be the one to cop it later. But to allow this man to speak like this and then walk out of the consulting room … The prospect was unbearable.

‘What’s the hold-up?’ asked Ferguson. ‘We all done?’

‘Give me a second. Lie still for me while I, uh …’

Her body followed her usual practice, on automatic, reaching for a cotton ball and bandaid to cover the needle’s puncture site. On the shelf, she noticed two glass ampoules of adrenaline lying in one of the plastic storage tubs. They kept some in each consulting room for use in an emergency anaphylaxis situation.

Paula pictured herself—as clear and precise as a training video—picking up the yellow ampoules one at a time. They would feel like glass bullets, cool and smooth in her palm. She would wrench the top off each one with a sharp yank of her wrist and draw the liquid up into a syringe. She would then turn around and inject the adrenaline into the catheter in Ferguson’s arm. Two one-millilitre doses would send him into extreme cardiac dysrhythmia and probably into full cardiac arrest, given his existing medical problems. The injection site would be explained by the catheter she was using to collect blood, and an autopsy would be unlikely to be incriminating. It could be done.

Paula stood very still to listen to her own sensible voice in her head. The voice spoke slowly and calmly, leaning into the rhythm of the phrases to gain some control over her ragged breathing.

Injecting the adrenaline into this man would be murder. A doctor couldn’t deliberately kill a patient like that. She was not that person. This was not her. This was grief. This was crazy thinking. If Rochelle was in danger, Paula could not hold herself responsible. Not to this degree. She was not a person who would murder a human being, however foul a human being, however dangerous he was.

She took a deep breath, squared her shoulders, stern with herself, then picked up the cotton ball and bandaid.

Right at that moment, Ferguson started going off at the mouth again.