Americas love affair with LSD did not begin in Haight-Ashbury or during the summer of love. Instead it was seeded ... in Midwestern laboratories and government offices, where it comprised one strand of an extensive germ warfare programme. Errol Morriss splendidly clammy, mysterious docu-drama Wormwood reopens the file on Frank Olson, a jobbing biochemist who fell to his death from a New York hotel. At the time (December 1953) Olsons death was ruled to be suicide. But 20 years later evidence emerged that complicated the official verdict and prompted Olsons family to sue the federal government. Even today elderly Eric Olson is in search of a definitive answer. He casts himself in the role of a Cold War Hamlet, haunted and harried by his fathers ghost. So what became of luckless Frank Olson? Did he fall or was he pushed? Infuriatingly perhaps fittingly we will have to wait to find out. For Morriss docu-drama is a six-part series, commissioned by Netflix. So were left to blunder on, hands outstretched, past pensive Eric Olson and ... through spooky archive footage of a 1970s congressional hearing where sleazy Colonel Ruwet surely the villain of the piece sits with his back to the camera, meaning that we can only see his starched collar and his bald spot and the hint of a smile when he responds to a question. Who, then, can predict how this investigation turns out?