THERE is a lot going on in The Fifth Step, David Ireland’s play about a young alcoholic navigating his way through the AA programme.

Father-son relationships, faith, trauma, sexuality – it’s all in there, delivered in a series of conversations between Luka (Slow Horses star, Emmy award nominee and general all-round hot ticket on stage and screen Jack Lowden) and his sponsor James (Sean Gilder, whose huge body of work includes memorable roles in Shameless and Hornblower).

Both men give compelling performances in this National Theatre of Scotland two-hander, directed by Fin Der Hertog, which lasts around 90 minutes with no interval.

(Image: Mihaela Bodlovic)

(Image: Mihaela Bodlovic)

Lowden, as the jumpy, earnest young man desperately trying to find a way through his addiction, is at times hilarious, at others, absolutely heartbreaking.

READ NEXT: Slow Horses star attacks Scottish arts funding cuts on stage in Glasgow

Gilder, as the older but not necessarily, it turns out, wiser mentor, is excellent as the happily-married-father-of-one slowly unravelling, mentally and physically as he guides his younger friend through the 12 steps of the Alcoholics Anonymous programme.

(Image: Simon Murphy)

(The title refers to the “confession” step, where members acknowledge the harm they have caused to themselves and others in pursuit of alcohol – or, as James puts it: ‘The point is to divest yourself of shame, it’s about getting clean.'”

(Image: MIHAELA BODLOVIC)

A clever, rotating set, designed by Milla Clarke, moves the actors and action between the various spots – café, gym, AA meeting room - where Luka and James talk, argue, joke around, spill secrets and fight.

Ireland’s surreal imagination and dark humour take the story to some brilliantly weird places, but ultimately it’s a thoughtful, emotional examination of what it means to be a man, to have faith, and to find a way of coming to terms with your past.

The Fifth Step is at the Pavilion until Saturday.