No stars, minimal hype, a long afternoon into the South Bank night: the National Theatre is staging back to back two little-known plays by two 20th-century American masters, and the result is a bit like opening an old trunk in the attic to find pristinely laundered shirts and suits, and perhaps a pair of perfect spats. Beyond the Horizon by Eugene O'Neill and Spring Storm by Tennessee Williams are early works by each playwright, from 1920 and 1937 respectively, and while the O'Neill feels somewhat stretched, even lugubrious, it's astonishing to learn that Williams' ebullient piece was first performed only in 1996.