The Traverse's commitment to enabling new voices - both playwrights and previously unheard stories - has led to the theatre becoming an important supporter of women's work: Gut presents a subject that has rarely been shown on the stage, the power of a mother's love and how fear for a child's safety can become overwhelming and destructive. Following a moment of anxiety, Maddy (Kirsty Stuart) recognises the dangers facing her young son and, once the fear has attacked her sense of self, she begins to descend into a horror that, ultimately, makes her the threat.

Frances Poet's script audaciously addresses two themes - the power of a mother's love, expressed eloquently in a speech by her husband, Rory (Peter Collins), and the power of fear to destroy everything. Gut is the tragedy of Maddy, a good mother who allows the fear of child abuse to remove her dignity as a person. The ambition sometimes falters - the presence of 'the stranger' (George Anton) is menacing but too obviously a figment of Maddy's paranoia, and the tension between a mother who loves and a mother who abuses her son is too easily resolved. It is as if the script flinches at the thought of Maddy's responsibility and allows her a happy ending without examining the consequences of her single act of violence.

Yet it is in the forensic attention to the detail of Maddy's decline that Poet is most effective. Driven by a desire to protect, Maddy abandons her job, her mother-in-law, social relationships and her loving relationship with her husband - his responsibility for her decline isn't sufficiently explored. That the scenography is generic – children's toys scattered across the stage, a table that stands in as home and a cafe – and the various 'strangers' played by George Anton are variations on a threatening presence diffuses the tension, making Maddy's shift to abuser abrupt and her redemption unconvincing. Passages of eloquence vie with overplayed symbolism, the naturalistic style of early scenes disappearing into melodramatic horror unevenly.

Gut contains an important story, yet struggles to reconcile its immense themes within a theatrical format that has been developed for less intimate topics. The script has moments of intense meaning, a meaning that is sometimes too much for the production to contain. But as part of the Traverse's commitment to 'new writing', it suggests that theatre can reclaim its status as a forum for exposing the dangers that lurk beneath good intentions and become the focus for public discussion.

Reviewed at the Traverse, Edinburgh. Tron, Glasgow, 16-19 May.