Children Of Hercules/Treasure Island, The Scoop, London SE1

The joy of this alfresco occasion stems from its canny responsiveness to the extraordinary diversity of the audience, which ranges from seasoned theatregoers with their wine and picnics to casual passers-by.

Willmott and Steam Industry have developed a style of writing and performance of full-bodied vigour and sophisticated teasing. The amphitheatre becomes a dynamic debating chamber - for The Children of Hercules. Pursued by their father's enemy, Eurystheus, the offspring of the legendary hero are repeatedly denied asylum until they reach Marathon. This impassioned staging does not need to force the contemporary parallels, as the ruler Demophon (whose moral discomfort is vividly conveyed in Willmott's edgy portrayal) grapples with the dilemmas. It is civilised to shelter political refugees, but how can this be reconciled with the duty of protecting your own citizens who will thereby come under attack? The alert, confrontational production throws such questions out to the audience. There's a jolting moment toward the close when Hercules' mother, Alkmene, calls for savage vengeance against the captured Eurystheus.

Treasure Island, in this account, is a delightful blend of the salty and the silly. It must be the first stage-version of Stevenson's novel in which the craving for cheese of the marooned Ben Gunn (Nick Smithers's loopily obsessive Brummie) is turned into a lavish musical extravaganza. It makes another droll innovation in equipping the Hispaniola with a partly female crew, headed by Bea Holland's feisty and un-nautical Lady Jacqueline Trelawney.

Thursday-Sunday to 14 August