If anyone should doubt the toxic nature of the Russian government of Vladimir Putin, they need look no further than the case of anti-Putin activist, Vladimir Kara-Murza. On two separate occasions in the past four years, Kara-Murza has been subjected to two different poisons which, untreated, would almost certainly have killed this outspoken Kremlin critic. His recovery the first time left him in a coma for a week, a gap in his memory which spanned a full month, plus more time to regain the full use of his physiology. Amazingly undaunted, Vladimir returned to his homeland, only to be surreptitiously poisoned a second time. Even with this repeated incident, he is determined to press on with his protests.
CBS News 60 Minutes has made a thorough investigation of this case, including several interviews handled by their correspondent, Lesley Stahl, plus an "Overtime" segment which deals with some of the backstory behind the television segment. I cannot embed the video here, but the stories are available through the above links, and I recommend both to your attention.