Nowhere is safe

‘The poison, how did he administer it to you?’
‘On the Potus Terrae, in the observation gallery. It was the only opportunity he had. My own quarters were hermetically sealed.’
‘But you drank no wine nor took anything else from his hand.’
‘You did,’ said Veritus, ‘and you live. The wine was not poisoned.’
‘The pressure leak,’ said Wienand. ‘But our servo-skulls detected nothing in the gas mix that should have caused you harm, and like the wine, I was exposed. I am still fine. I have been thoroughly examined.’
Veritus nodded weakly. His papery skin rasped on the crisp sheets. ‘The gas mix was non-toxic on its own, but it contained an agent that reacted with the compounds my suit produces for me to breathe. A single molecular binding altered my serums to a form indistinguishable from the benevolent variety, but enough to turn them deadly in my system. It reversed my anti-gerontic medicines, so they attacked my genetic code where they should have preserved. By the time I was ill enough to notice, the damage was irreparable. I am too old to recover from this.’ He laughed drily. ‘Vangorich is clever. He used what was keeping me alive to kill me.’

"The Beheading"