THE game’s still afoot but now the game’s on another foot after illness forced George Williams to step down from playing Dr John Watson, the everyman hero of Alexander Wright’s contemporary, interactive drama inspired by Sir Arthur Conan Doyle’s detective stories.

At three days’ notice, one of Wright’s Flanagan Collective stalwarts, Ed Wren, took over and his familiarity with the company’s house style of audience participation and thinking on your feet, while making serious points too, means that he is just what the doctor ordered.

Chemistry between Dominic Allen’s mercurial Sherlock Holmes and Wren’s stoical Dr Watson is all important, and they are just as well matched as Allen and Williams were. Wren is graver, more intense,his Watson even more frustrated by Holmes, but then it is noticeable how Allen, always such a live-wire on stage, has taken Holmes to another level of fierce sparring since the first week.

Sherlock is franker, wilder, harder shelled, shooting from the lip in his combative exchanges with the assembled ranks in the rows of council-chamber seas. He is not averse to belittling or mocking them, as well as teasing them, such as when he talks of one woman’s “gallons of perfume”. Such is Allen’s skill, however, that this is humorous rather than hurtful, as he flickers and flares up, while Wren’s loyal foil Watson is the reliable rock.

Given the ease of the anagram to unravel, it will not spoil the play and its parlour games to reveal that Allen begins in the guise of a manic Germanic professor of criminology, Selohm Socklehr, newly appointed to a post at the fledgling University of York in its first year, 1963. Again, Allen has added a fifth gear to this role, working over the audience with merciless intemperance at the Teutonic tutor’s lecture on Holmes’s science of deduction and analysis.

The show is driven equally by the relationship between Allen and the audience as that of Holmes and Watson, and writer Wright works Holmes and audience hard; even the interval involves a search for clues to assist Holmes in his pursuit of his arch nemesis Professor Moriarty.

The more you are prepared to join in, the better, be it throwing yourself into a jazz-age dance or bonding in teams to find clues. “You are almost wise in understanding your stupidity,” says a scolding Holmes to one group, whose members laugh as loudly as everyone around them.

You will have to discover for yourself why, how and in what form the spidery Moriarty fits into the story, but Allen’s Holmes is as much in combat with himself as his nemesis, saying how he cannot live without brain-work as he asks what is the point of having powers without the field to use them.

This is where Wright excels with his combination of Fringe humour (you will discover the real name of the Dalai Lama and hear an in-joke about Holy Moly and The Crackers, a York band) and his contemplation of why we keep seeking superheroes when we would be better giving our all to our own lives.

Sherlock Holmes: A Working Hypothesis, The Flanagan Collective, York Guildhall Council Chamber, until September 21. Box office: 01904 623568 or