T he air hangs heavy in Alma, a drinking club in 1950s Port of Spain, Trinidad. Heat and rum bring their own kind of languor – but in Martina Laird’s play, change is coming, both within a fractured family and in the wider world. Alma is managed by a mother and daughter. Ellen Thomas gives the indomitable Pearl a basilisk glare but not maternal instincts (“the only thing I done wrong is to make children dat not worth nothing”). Ruby (an exuberant, citrussy Cat White) runs a honeypot scam on tourists, but doesn’t intend to “stay here in downtown hell”. When Pearl’s long-abandoned son Diamond arrives, tensions seethe. The RSC’s content warnings flag up incest – so it’s no surprise when Ruby and Diamond catch each other’s glance. She stands in golden lamplight, and he draws close, moth to flame. Martins Imhangbe’s towering Diamond moves in an unhurried, proprietary roll, teetering and then rising on his toes. Unhurried … Martins Imhangbe as Diamond in Driftwood at the Other Place, Stratford-upon-Avon.…