In silent invitation Yuuto carefully pushed a chair out with the battered toe of one boot. It seemed this would be a conversation requiring reflection and shared scrutiny. Presuming, of course, that the detached ex-assassin was willing to share with her partner. Yuuto did not delude himself that River shared half her thoughts and experiences with him. It was to be expected, he supposed, in the pitiless dictatorship permeating every shadow of the World Of Progress. Still he consumed what tidbits she offered like a wary stray cat. It was what he was good at, after all, and too easy to slide into the familiar dynamic. Each conformed to their complex yet intrinsic nature.
"An injection? Like a medicine or recreational drug?" The latter seemed unlikely, though some of the most brilliant beings had taken drastic measures in search of stability. None of the (admittedly limited) information he possessed suggested that Tempus was mad. The implications were myriad and morbid. Was the ancient being ill? Time Lords were not human and could not fall to the same disease and weakness. Was there even a scientist alive who understood the race enough to develop a vaccine? Did the other Doctors know of their counterpart's condition? So many questions... and the source from which to mine answers was inviolable. He did not offer any of these to River as she would have already asked them of herself.
"Murdering people doesn't seem to be something he's comfortable with." A bitter smile tugged one corner of his mouth up. These compassionate heroes always thought themselves untouched by dark impulses until they were faced with the great choice. Then they performed the bloody task as fiercely as villains. The difference was that they never forgave themselves--- nor stopped counting the bodies of their enemies. Yuuto had long ago learned to jettison the guilt of every life he ended along with the Zeronos Cards. He owned too much sorrow already without that wealth of pain. "I'm prepared in case he decides we make good exceptions." To defend himself, yes. He would never be braced for harming a good person.