Who was the man who stood defiantly in front of the tanks in Tiananmen Square in 1989 holding a plastic shopping bag? And what has happened to him? The play opens with Stephen Campbell Moore as Joe Schofield, an American photojournalist, snapping the historic event from a hotel bedroom and being rushed by the police.
Next thing we know, it's 2012 and Joe is supposed to be on the tail of the presidential election campaign in New York but is drawn back to the identity question by a cryptic message in a Beijing newspaper.
His involvement is further complicated by a burgeoning friendship/romance with Claudie Blakley's flaky marketing liaison executive who is at first working for a credit card company but who badly blows a key presentation (done with exquisite hesitancy) on new consumer markets and ends up working for Tesco.
At the same time, he's hounded by a demanding editor (Trevor Cooper) and a tough-as-teak wordsmith colleague (Sean Gilder) while chasing down leads in Beijing provided by Benedict Wong's Chinese English teacher - haunted by a girl emanating from his fridge - and his dapper factory-owning brother (David KS Tse).
The play's not impossible to follow - it's highly enjoyable, scene by scene - but nor is it impeccably constructed. Dramatic momentum is intermittent and depends on a series of sudden twists, the best of which concerns a misunderstood collaboration on finding the "tank man".
Es Devlin's extraordinary revolving cubic design - lit up with video projections and photographic imagery by Finn Ross and Tim Lutkin, with a pulsating soundtrack by Carolyn Downing - whirls us from Beijing to New York, from the campaign trail with Nancy Crane's hilarious Democratic candidate to back street dives and front offices; there's even a multiplicity of seemingly interlocking interiors.
It's not often you see a new play with a cast of 12 actors (eight of whom play two roles or more) and such a narrative sweep. Campbell Moore holds it together with a charming, well-focussed performance, buttressed by Wong's impassioned key contact (who falls foul of the authorities himself) and Elizabeth Chan's vivid girlfriend/ghost.
Karl Collins bats cleverly on both sides of the cultural divide, and there are some deft quick-change Chinese cameos from Vera Chok, Sarah Lam and Andrew Leung as a young idealist to keep the stage busy and well-populated.