Losing a child, surely, must be any parent’s worst nightmare. I’ve thankfully never had to endure the worry this possibility must cultivate, as I don’t have any children yet, and so can’t imagine how the thought of potentially losing them must feel. In Frozen, that fear is realised, as Nancy’s (Suranne Jones) daughter Rhona goes missing. They search for five years, before known paedophile Ralph Wantage (Jason Watkins) is arrested and admits to sexually abusing and then murdering numerous young girls, including Rhona. We watch as Nancy and her family journey through grief, but Frozen also explores the psyche of the killer. Agnetha (Nina Sosanya) is a psychiatrist writing a thesis on, essentially, what makes killers kill. She includes Wantage in her study, and we get a chilling insight into the mind of a murderer as she attempts to understand just why he did what he did, and what made him who he is.

Jones plays the understandably desperate and furious Nancy painfully well. Her hurt is palpable. I am unable to understand the fears and joys that motherhood brings, but I think Jones brought me pretty close with her admirable portrayal of a mother in anguish. However, the stand out performance, for me, was Watkins’ irreparable disturbed Ralph. Psychotic, emotionally detached, morally depraved, Watkins gives Ralph a socially disconnected quality that makes him seem almost inhuman. It is comforting at first, to see someone capable of such atrocities come across as so psychologically far from the rest of us. But as he spends time with Agnetha, his humanity weasels its way back in, and terrifyingly, he becomes recognisable – one of us. Sosanya as New Yorker Agnetha is precise and thorough with a dark sense of humour. Haunted by her own wrongdoings, though nowhere near as horrendous as Wantage’s, she is impartial and forgiving of Ralph – a sensible and unbiased voice of reason. All three, although never in scenes altogether, pair brilliantly with each other, and make for a strong cast of juxtaposed characters.

Written by Bryony Lavery, and produced at both the National Theatre and on Broadway (and nominated for four Tony Awards), Frozen is heart-breaking, and Rhona’s story is horrendous – but it also attempts to understand how such tragedies occur, and in turn, how we are to recognise and even perhaps prevent them happening again. I’m not sure if it’s comforting or disturbing to consider the case that Agnetha argues, that ‘evil’ is not something that some are simply born as, it’s something we become capable of through circumstance – but it makes for interesting viewing. Both frightening and enlightening in equal measure, Frozen won’t exactly quash the last of those January blues, but with stunning visuals aided by Paul Wills’ set design and Jon Clark’s lighting – it bravely seeks to make sense of something we can’t understand, and tells of a mother’s unimaginable struggle to do the same in order to heal.

Frozen is playing at the Theatre Royal Haymarket until 5 May 2018

Photo: Johan Persson