"Yes." Somehow, through the whole explanation, Claudius hadn't mentioned the trivial reality of his pain, or his promise that if the pain started again he'd seek out Lan Wangji directly. It hasn't, not anything like at its original intensity, just enough to confirm the earliest experiments -- and he hasn't felt it again in some time. "But I did note that the oldest samples would stay at rest regardless, which suggests there's a limit to how long they can act outside the body. It gives me an idea of what to attempt when I ask Crowley for help with the cure. I've no wish to grieve thee, if thou wouldst grieve my death ... so I can do little else but try."