Hannah Walters carries Amazing Grace, a helpline drama of raw sincerity

Hannah Walters delivers a terrific performance as a helpline counsellor trying to save a suicidal caller in Amazing Grace, Daniel P Lewis's intimate, microscale drama in which Lewis also stars and writes the screenplay.

The premise is spare. Working a night shift on a helpline, counsellor Grace takes a call from Walter (Lewis), an isolated working-class man beset by trauma and loneliness, who is contemplating killing himself. Grace quickly establishes that Walter is in profound emotional distress. He repeatedly hangs up on her whenever her probing questions cut too close; just as persistently, he calls back, until he feels safe enough to speak about the root causes of his anguish and to accept help. That fragile progress is then threatened from another direction, as the violence that has always been part of Walter's life erupts once more.

What does the film do well?

The Guardian's review identifies sincerity as the film's core strength. Even a viewer who knew nothing about the production's background would likely sense, while watching, that Amazing Grace is a labour of love for some of its cast and crew — perhaps born, the review suggests, of a desire to show people in pain that help exists. That manifest sincerity and altruistic intent is so strongly palpable, the critic writes, that it somewhat wards off negative criticism.

The review's verdict on Walters is unambiguous: she is "a terrific Hannah Walters," the blazing centre of a film that essentially lives inside two voices on a phone line.

Where does it fall short?

The same review is candid about structural weaknesses, and the caveats matter as much as the praise.

• Repetition. Confining the action to Grace and Walter's conversations, then observing how Walter reacts increasingly self-destructively after each talk, locks the film into a rinse-and-repeat cycle of confession and reaction.
• Nowhere to go. Lewis's performance is dialled up to the max from the start, so it lacks room to develop over the long haul.
• Over-explaining flashbacks. The film keeps cutting away to somewhat strident flashbacks to explain what happened to Walter, instead of letting the revelations emerge through speech — a choice that undercuts the intimacy the two-hander format establishes.

So what?

The tension the review leaves unresolved is a familiar one for purpose-driven cinema: the worthiness of the intent does not automatically translate into dramatic craft. Walters's performance gives the film its heat, and the subject — a lonely man at the end of his tether, and the counsellor who will not let him go — gives it weight. Whether audiences seek it out may depend less on reviews than on the film's ability to reach the people it was evidently made for: those in pain who need to hear that help is out there.