Simon Stephens’s 2007 play is meant to be disturbing—and succeeds at it even in ways that Stephens may not have intended. Set in London during the first week of July 2005, Pornography comprises a string of more or less self-contained vignettes in which an angry employee commits corporate sabotage, siblings try incest, a professor leverages his power over a former student, an old lady samples online porn, and a teenager indulges antisocial fantasies. Then there’s the vignette involving a fictionalized version of Mohammad Sidique Khan, one of four British jihadists who attacked London’s transit system on July 7, 2005, killing 52 people. I think Stephens means to suggest a continuum between his Khan and the lonely, socially alienated souls in the other scenes: same disease, greater and lesser degrees of virulence. But a continuum implies an equivalency, and that’s hard to accept. Can you really draw a line from, say, the corporate saboteur to a mass murderer? Creepier still is the implication that the crimes committed by the other characters somehow led to Khan’s atrocity. Well, then, if I have all these reservations about the show, why am I recommending it? Partly because Robin Witt’s production for Steep Theatre is so incredibly sharp, with nothing but smart, clear-eyed performances. And partly because it’s worth something to be so unsettled.