The evening before he must be present in Birmingham to supervise the largest non-nuclear facility and non-military concrete pour in European history, construction foreman Ivan Locke learns that Bethan (a colleague from a job in Croydon with whom he cheated on his wife seven months previously, resulting in her becoming pregnant) has gone into premature labour.

Over the course of the two-hour drive from Birmingham to London, Locke holds a total of 36 phone calls with his boss Gareth; his work trainee Donal; his wife of 15 years Katrina, to whom he confesses his infidelity; his sons Eddie and Sean, who call him separately with updates on the football match he originally planned to watch with them, and later Katrina's breakdown; maternity unit personnel Sister Margaret and Halil Gullu, who are working with Bethan through troubling complications; the council head Cassidy and local police authority PC Davids, who are required for the road closures needed to allow the 225+ concrete trucks to properly access the site; and Bethan, whom he reassures during labour.

He coaches Donal through the preparation of the pour despite major setbacks and has imaginary conversations with his dead father, whom he envisions (off-screen) as a passenger in his car.

The critical consensus states, "A one-man show set in a confined location, Locke demands a powerful performance—and gets it from a never-more-compelling Tom Hardy.

[17] A French adaptation titled Cross Away, directed by Gilles Bourdos and starring Vincent Lindon, was in post-production as of February 2024[update].