An angel doesn't come crashing through the ceiling here as happens in his masterpiece, Angels in America, which will be revived by the National Theatre next year. But a bust of Guiseppe Garibaldi, the Italian nationalist, does get punched into the wall, leaving a gaping hole, during one of the Marcantonio family's many voluble rows in this latest Tony Kushner work which was unveiled in Minneapolis in 2009 and now, several drafts on, receives its British premiere in Michael Boyd's extremely adroit and passionately acted production at Hampstead.

Angels probes the psyche of Ronald Reagan's America in a fluid “fantasia” form that allows characters to meet in each other's dreams as it ranges between New York and the Kremlin, Antarctica and Heaven. By contrast, the new three-and-half-hour piece (its snappy moniker fuses the titles of works by Shaw and Mary Baker Eddy) is firmly set in 2007 in a Brooklyn brownstone and conducts its examination of the state of the American left from within that country's great tradition of brutal, realist family drama which embraces Eugene O'Neill and Arthur Miller. The patriarch of the Italian-American clan is 72 year old Gus (David Calder), a retired longshoreman and Communist Party union organizer. He's already made one attempt on his life and when he decides on a second suicide bid, he summons his three troubled children and their appendages to a family council. He pleads incipient Alzheimer's but he's still vigorously pursuing his hobby of translating Horace...

In the first scene, the gay son, Pill (Richard Clothier) mentions that he's just seen Shaw's Major Barbara and describes its effect on him: “Dizzying, a head rush, sort of like... oh, I dunno poppers, or speed or E”. Then he calmly disses Shaw as “a sentimental pseudo-socialist, peddling an idealist conception of history”. “Oh yeah, baby, talk commie talk,” replies Eli (excellent Luke Newberry) the Yale-educated rent-boy with whom he's infatuated. It's a teasingly witty and knowing moment that sets us up for an evening that consists, in part, of raucous, rampantly well-read dialectical slanging matches and brain-knottingly baroque family entanglements. You laugh out loud at how surprised you aren't when heavily pregnant Maeve ((Sirine Saba) – married to Gus's daughter and inseminated by his other son – complains that it's “not exactly a bull market for us apophatic theologians with, you know, pronounced kataphatic inclinations”. The impenetrability of that is Kushner's delicious, self-parodying gag.