potion thaumaturgy

Which made what I was about to do difficult, as well as painful.
And necessary.
I put a hand on his shoulder and said, “Hang in there, man. Once we get through this, maybe we should get Wild Bill and Yoshimo and go camping again or something.”
“Sure,” he said in a neutral voice. “That might be good.”
He didn’t notice the little ampule in my hand, or how it broke and spread the liquid inside onto his cloak and my skin. No one would notice one extra splash of liquid on his clothes. I lowered my hand, palming the broken ampule, and Ramirez didn’t notice a thing.
Why would he?
He was a friend. He trusted me.
I felt sick.

Peace Talks Chapter 25, Page 239


I took a second ampule, identical to the one I’d crushed on Ramirez, out of my suit’s inner pocket and crushed it in the same hand I had the first. I’d been careful not to clean that spot on my palm, and the potion in the fresh ampule mixed with the residue from the one I’d slapped on Ramirez.
My hand quivered, clenched spasmodically once, and suddenly felt heavy, as if a large, slightly damp beach towel had been draped across it.
“On me,” I whispered. “Here we go.”
And then I spread my fingers out as if guiding a marionette, started wiggling them, and Lara and I started hauling Thomas out, Freydis close behind us.
The potion I’d slipped onto Ramirez’s cloak had been half of the brew. The stuff currently on my hand was the other half. The two were magically linked by a drop of my blood, the most powerful agent for magical bindings known to reality. With that bond formed, it was a simple enough trick to send a pulse of energy from my hand over to poor Carlos’s cloak.
The grey cloth abruptly flared, whipped wildly around as if in a hurricane wind, and promptly dragged the young Warden off his feet and across the floor—toward the back of the hall, in the opposite direction of the front door.
People and not-people let out noises of distress. Several dozen security teams bolted for their primaries. A lot of folks got tackled to the floor by their own retainers. I caught a glimpse of Molly being surrounded by a group of Sidhe and hustled to one side of the room—and I recognized one of them, the goddamned Redcap. The murderous Sidhe assassin had traded in his baseball cap for a scarlet headband of a leather whose origins I shuddered to consider.
We moved through the chaos as Carlos struggled with his cloak. He managed to unfasten it, and the damned thing promptly began flapping around like an enormous bat.
And it worked. The room stayed black-and-white. Everyone’s paranoia was so focused on the potential threat that they didn’t have enough cognitive cycles left to be paranoid about us.

Peace Talks Chapter 28, Page 270-271