From Xan Brooks’ Guardian review, dated 9.2.17: “America’s love affair with LSD did not begin in Haight-Ashbury or during the summer of love, with tie-dyed flower children frolicking in city parks. Instead it was seeded in less airy surroundings; in Midwestern laboratories and government offices, where it comprised one strand of an extensive germ warfare programme. At the rustic log club-house, underneath the mounted elk’s head, revellers drank spiked punch poured by CIA factotums. Inevitably some of these victims went clean off the rails.

Wormwood, Errol Morris’s splendidly clammy, mysterious docudrama, reopens the file on Frank Olson, a jobbing biochemist who fell to his death from a New York hotel. At the time (December 1953) Olson’s death was ruled to be suicide. But 20 years later evidence emerged that complicated the official verdict and prompted Olson’s 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 father’s ghost.

“Morris has spent his career patrolling these dirty tide-pools of American history; lifting up rocks, peering at the wildlife. With Wormwood, though, he appears intent on broadening his repertoire. Gone is the straight-down-the-barrel ‘Interrotron’ camera used to frame his subjects on films like The Fog of War and The Thin Blue Line, replaced with a multiple set-up and interviews that sometimes play out in split screen. There are reconstructions here, too, with Peter Sarsgaard playing Olson Sr. and Bob Balaban cast as a CIA shrink. Elsewhere Tim Blake Nelson crops up as the government poisoner complete with a speech impediment and the sort of ghastly smile that suggests he may have recently sipped from the wrong glass.”