It’s not often that a play concerning a man under suspicion of torturing and killing children is cast as a comedy. But such is the macabre setup in Martin McDonagh’s The Pillowman, which returns to London after both its 2004 Olivier Award win for Best New Play and a run on Broadway. Predominately set in an interrogation room, McDonagh, who also wrote and directed Three Billboards Outside Ebbing, Missouri; In Bruges; and Seven Psychopaths, has earned a reputation as a preeminent storyteller. Starring Aaron Taylor-Johnson, the play dangles the age-old question of whether art imitates life, or if something more malevolent is at play? —B.A.