Michael Sheen and Maria Bello give brave performances as a married couple trying to come to terms with the quite incomprehensible. They shared a family home, yet found words increasingly hard to come by. Every strained dinner conversation was another reminder of the extent to which they’d used their son as a panacea; once hoping that a life of recitals and college tuition might somehow bridge the void. Now they seemed more like middle-aged strangers than partners, bound by a child they barely heard from. Vacations first postponed, then cancelled. Messages left were seldom returned, and even those that were took the form of vacuous pleasantries. Family, like marriage, becomes just another routine when you stop asking anything of one another, and how sad it is that it took their son killing himself and his classmates to remind them of that.

Films can be so focused on the event that they forget to consider what happens afterwards. Beautiful Boy exists almost entirely in that forgotten space, so much so that our only glimpses of the son are in a phone call on the eve of his death. Had his parents thought to truly listen, they might have sensed his growing preoccupation. They did not; there would always be tomorrow. Bill (Sheen) cut him short in favour of the evening paper, just as his mother (Bello) could think only to remind him to study hard and stay in school. Such words, imparting neither love nor warmth, are unlikely to have been those she’d have chosen with prescience, but then life always did have a way with irony.

By choosing to look beyond their tortured son, the film imagines instead what two perfect strangers might do when faced with the truth. Within minutes of the police making the announcement, a sea of reporters and cameras arrived to camp out on their lawn. The couple hide upstairs in the darkness of their son’s bedroom, finding stories and artefacts, but few explanations. How could they? Senseless acts are both more than the sum of their parts and, inversely, nothing at all. As parents, it must have been maddening to try and reason with that, no less so for it having been committed by a child they must now accept they hardly even knew.

Before long, they go to stay with Kate’s brother, who has a young family of his own and accommodates them as best he can. Bill quickly retreats to the comforting routines of work, only to find his presence there drawing the stares of co-workers who mistake judgement for concern. His wife, increasingly adrift, grows dependant on mothering her nephew. The fairytales that once delighted her own son are now gifted to him, in bedtime rituals that try to make sense of where she might have gone wrong. Late one night, as they dissect their roles, the hand-held camera draws in closer. Bill snaps. “I wish to god we hadn’t had him” he rages, throwing his wife to the floor. “I wish we hadn’t fucking had him”.

There are brief moments of relief. The couple break into unbridled laughter in a dinky motel room, meeting over cheap vending-machine snacks that kindle some forgotten passion. In all other respects, this remains a bleak and understated film, as arguably it must. There’s always the risk that drawing too much drama from a tragedy can leave it a silly artifice of grief, and Shawn Ku directs accordingly, with caution that leans on silence over words. Just about everything he wishes to convey can be found in the motionless prayers of a father, or a wife’s resentment that seems to extinguish all hope of redemption. To lose a child is to ask questions that cannot hope to yield answers, and Beautiful Boy must content itself with documenting the cogs’ futile spin.