Naked racism is an ugly thing, but veiled can be just as intimidating. Especially in recently formed Dilated Theatre company's visceral, accomplished version of Barrie Keefe's 1979 play SUS at the Lion and the Unicorn.

Based around true events, SUS opens a door onto an example of petty and vindictive semi-institutionalised racism in London in the late 70s and early 80s typified by the so-called 'Sus' law. This meant officers could stop and search and pick up anyone off the street who they suspected of criminal activity but it was a power too often abused.

Alexander Neal excels as repellant white police officer Karn, psychologically torturing black husband and father of three Delroy (Wole Sawyerr) in designer Celestine Healy's bleak police office. For all his pretentions of culture, the holidays to Europe he takes with his wife, he's a vile bigot who tells Delroy he should have gone back home when he had the chance - regardless of the fact Delroy was born in England.

Sawyerr affectingly portrays Delroy’s descent from casual unconcern over what he thinks is just another 'Sus' pickup to anguish and suppressed rage when he realises it's actually linked to his wife's death. The only distraction is his accent which has tinges of the North running through the London-West Indian delivery - but that's easily ignored.

Nason Crone is a good stooge as Wilby, Karn’s accomplice in the bullying. The duo’s shifting sense of menace is perfectly pitched and when Karn explodes with venom in Delroy's face after nearly half an hour of feigned amiability, tears actually sprang to my eyes.

Now, in an age of apparent equality, the casual use of derogatory phrases feels shocking. Almost as shocking is the fact that today, black people are seven times more likely to be picked up by police under the Terrorism Act - the point hammered home by a projection at the close of the one and half hour show. This is a powerful piece: tersely directed by Paul Tomlinson, brutally acted, well worth the trip to Kentish Town.

- Vicky Ellis