HE FELT POSITIVELY nervous returning to see Wildsmith that evening. That was absurd. It had been weeks since the man had turned up at his flat: he’d probably forgotten about Aaron’s existence. Or decided he was part of some kind of police conspiracy, one of the two.

He knocked, and could have sworn he heard an expletive from the other side of the door. Wildsmith answered after a moment. He was in his shirtsleeves, both rolled up to the elbow, despite the late November damp and chill.

“Good Lord. Detective Sergeant. Was I expecting you?”

“May I come in?”

“But of course.” Wildsmith stepped back and gestured welcome.

There was a good fire going. “Not stingeing on coal, I see. Graphology paying well?”

Wildsmith lifted his left arm in reply. It was encased in leather straps from the elbow to the wrist, capped at the end by the holder of his split hook, which had a pencil clamped in it. Aaron had seen similar devices often, but usually just as the metal end poking out of a coat sleeve. Now he saw Wildsmith’s forearm—pale flesh, a little soft, sprinkled with copper hair—strapped around with leather, and felt this was an indignity or an intimacy to which he had no right.

“This thing is blasted uncomfortable under every jacket I own,” Wildsmith explained. “The sleeves are all too tight and the buckles catch, and it’s such a flaming nuisance I sometimes throw caution to the wind and put the fire on. What can I do for you? Tea? Kettle’s just on.”

“You astonish me,” Aaron said, and was a little too pleased to win a startled grin. “Yes, tea, please, if this is a convenient time for a chat.”

“By all means.” Wildsmith gestured at Aaron’s usual chair—not usual, he’d only been here twice—cranked the device to drop the pencil, and went to the tap. His right arm, Aaron couldn’t help observing, seemed significantly more muscular. Use, of course.

Aaron moved over to the table in a vague sort of way rather than sitting at once, in order to glance at the sheets of paper there, covered in writing that looked a little childish in the determined yet uncontrolled shapes. “Practising?”

“Mmm. I spent ages trying to write with my right hand because everyone assured me that would be best, and I’m sick of it, so I need to get used to this thing.”

“Why are you sick of it?”

“Because I’m left-handed,” Wildsmith said with a snap. “You write with the wrong hand all the time, see how you like it. It reminds me of school. I want my left back, or at least the feeling of using my left.”

Aaron flexed his own right hand. “I see.”