Eyes wide open, he looks down. Dirty hands, dirty knife, clean flame. No needles, no spoons (it's easier that way). Just the skittering fall of the violin's vertigo reel and the clear liquid in its little bottle. Here, now, for him, it's water. For Holmes, alone in his squalid room above the pub, it's a seven percent solution.
It's a key to a door that he's locked, barred, bricked up; that Holmes has left ajar.
The trick, the craft, of acting is in pointing out the contradictions. Letting the light in and letting the darkness out. The way he's playing Holmes makes it about what's allowed and what's forbidden and how you set yourself outside the law because you know better. Makes it about what you want and what you can have. He's taught himself not to want this any more, just like Holmes has taught himself not to want Watson any more. (He's trying to teach himself not to want Jude, not to want more.)
He still remembers that first hit, how everything opened up, like the roof lifting off to reveal another dimension. He still remembers that last hit, how everything welled up, like the ground beneath him splitting and sending him down to the depths.
Here, being Holmes, he's trying to catch himself on the precipice, abyss opening, cosmos opening, light and dark, flight and fall, letting go. He's got a plethora of reasons not to do this: but he's not himself right now, he's Holmes, and Holmes has different taboos.
Holmes is free to marvel at the shiny suppleness, the appalling clarity, the sheer power of his unlocked mind. Holmes is arrogant (okay, that's one thing they have in common) and petty and passionate and bored to distraction by the mundane. Holmes fights and drinks and drugs himself so he can stop thinking; so he can think another way. Holmes knows that there's nothing outside these peeling walls as fearsome as what's in his own head.
Holmes is too sharp, too smart (too straitlaced) to credit the ritual with any power, to think he's summoning anything from outside. Everything's inside, encrypted, coiled in the back-brain. Holmes just needs to set the world aside, forget Watson and Mary and everything else that blurs his focus. Holmes is (he is) a lens.
Holmes is telling himself there's no one left to care what he does. That's a difference between them. Another difference between them.
He sits there, pretending to be Holmes who's pretending to believe that the cocaine is going to open doors, let in light, clarify his memories and set them into a mosaic of meaning. He sits there remembering the exaltation, the dizzying flight, the sickening fall. He sits there not thinking about Jude, not letting Holmes think about Watson, because that's distraction and what he craves (what Holmes craves, and he's got to be Holmes for now) is clarity.
It'd be easier to keep Holmes outside, to let him skin-deep and no more; but it's not supposed to be easy. So he keeps pushing and stretching and letting Holmes in, letting Holmes's regard for Watson bleed over, letting his own desires play out, pretending it's just pretend.
Everything's inside, encrypted, coiled in the back-brain.
He waits for Guy's signal, swigs from the bottle, lets muscle-memory and his own past puppeteer him, feels the rush and reel and sway. Holmes is down the rabbit-hole now. Robert's still teetering on the edge.