The Overwhelming, National Theatre, London

Matthew Marsh's Jack, a well-intentioned political scientist from Illinois, naively arrives in Kigali with his new African-American writer-wife, Linda (Tanya Moodie), and his bolshie teenage son (outstanding newcomer Andrew Garfield). Jack is bent on saving his academic career by writing a book about his old college pal, Joseph, a Tutsi who has been writing to him about his Aids-related hospital work. Having held forth at an embassy party about individuals proactively changing history, Jack and Linda are soon out of their depth, campaigning to find out why Joseph has disappeared while unwittingly befriending militant extremists.

The Overwhelming follows Out Of Joint's other superb verbatim pieces investigating fraught political issues. Here though, documentary-style interviews are turned into a fictional drama, with echoes of A Dry White Season. There are wooden moments, with obtrusively inserted set speeches, but the wised-up inactivity of ambassadors and UN officials is sharply depressing while Stafford-Clark's strong ensemble (including Adura Onashile and Babou Ceesay, left) are grippingly driven.

To 8 August, 020 7452 3000, and touring