First-time director Stuart Hazeldine’s clever puzzle movie poses an intriguing question: what if eight job candidates, trapped in a secure room to compete for a coveted position with a powerful but secretive corporation, found that the final exam paper was blank? The Invigilator’s rules are simple: no talking to him or the armed guard, no spoiling of papers, no leaving the room. But what is the question? With the clock ticking, the film unspools in real time, and the archetypal candidates – White, Brown, Blonde, Deaf, Black, Brunette, Chinese Girl, Dark – reveal their personalities, ruthless ambition and hidden personal agendas through their starkly different reactions to the conundrum. Plot twists, lighting changes and shifts of tone work hard to sustain our attention, but the script sometimes becomes too involved in solving the structural challenges it has set itself. This distracts us from the characters themselves, as what started out as a short film stretches its material and our credulity to the limit.