F ran Kranz’s 2021 film Mass , featuring two sets of parents whose sons have died in a high-school massacre, was originally written as a play. Restored as such, in Carrie Cracknell’s production, it takes place in the backroom of a church where their across-the-table encounter encapsulates a pained instance of restorative justice. Gail (Lyndsey Marshal) and Jay (Adeel Akhtar) are the parents of Evan, one of 10 children murdered by the teenage shooter, Hayden, the son of Richard (Paul Hilton) and Linda (Monica Dolan), who then killed himself. Evan’s parents want to understand why Hayden committed such violence but there is also an unspoken sense of blame buzzing around them. Hayden’s parents address this first: we blame ourselves, they say, again and again, yet in one dangerous moment, they posit the notion of separating who their son was , and what he did .…