Watch TV Series Poisonous Liaisons online for free. Poison has long been a weapon of choice; in desperate cases of defense, to conquer jealousy, to gain a much-awaited inheritance and of course for revenge in a crime of passion. Through interviews with criminal experts and psychiatrists, Poisonous Liaisons will delve into the thought process of some of history’s most notorious criminals, revealing their methods and the short and long-term effects their substances had on victims.