When the Doctor handed over the screwdriver, he simply nodded, taking a few moments to look over this particular screwdriver to ensure that it was the same, or very nearly the same, as the one the doctor in his universe had. It didn't take long for him to find the correct setting. Without the constant drums pounding inside his head, Koschei was able to think quickly on his feet. There were times he even mirrored the Doctor himself in forming plans and solutions on the fly. Once ready, he pointed the screwdriver at the Doctor, pressed the button, and took the scan.
"I have, yes. There were times we struck out in different directions, but we always seemed to run into each other again whether by accident or on purpose." Koschei chuckled softly as he read the results. His face paled a bit. "Well, that's not good. To be expected coming from Time Lords, but still very not good." He let the Doctor see the results for himself as his mind started racing, putting together a possible antidote. "All right, tell me you have a fully stocked kitchen? And medicine cabinet." Without waiting for a reply, Koschei went directly to the refrigerator and started combing through it.