Before he snorts, shoots up or swallows, making the list forces him to stop, to think about what he’s about to do, and why he’s doing it. It forces him to estimate dosages, which in turn means anticipating the likely effects on his brain and body. He writes as carefully, as accurately as he can, even when his hands are shaking – if doesn’t have pen or paper he finds them, wherever he is.
The list is sometimes as simple as:
GHB (powder) 3g
or occasionally, more complicated:
benzoylmethylecgonine (insufflated) 75mg x2
He knows the list could be his epitaph.
As he writes, he imagines Mycroft reading over his shoulder, shaking his head. Sometimes it makes him cross out an item or two, or even toss the paper into the bin. Not often, though.
Once, he steals away to a secret haunt, the top floor of a derelict factory in Bow, and waits. It takes Mycroft one day to notice, two days to worry, and three days to find him. He's curled up on the stinking, stained mattress, stomach rumbling, when Mycroft lowers himself gently beside him. The list is tucked beneath the mattress, and Mycroft unfolds it without a word.
“I needed to know you’d live up to the bargain.”