To the bombastic strains of an especially excited American-accented announcer, Austin Michaels takes centre stage. Despite the dramatic introduction, and his faintly movie star-ish name, the hero of Blank Tiles is a dowdy, unassuming figure. Shuffling into position by his oversized Scrabble board, Austin warmly relays the delightfully comic story of his journey from his dear granny's sitting room to the esteemed podium of the Scrabble World Championships.

But early in Austin's monologue, cracks in the geniality begin to emerge. He stumbles, loses his place, and as the play unfolds, the audience begin to witness a tense, yet ill-fated battle between the cheerful disposition of the lovable Austin and the merciless ravages of Alzheimer's Disease.

Blank Tiles is a remarkably well-crafted piece of theatre. Dylan Cole's writing is delightfully subtle: even in Austin's rambling tangents, small hints reveal bittersweet details whose significance is hidden even from himself. The production's use of the giant Scrabble board as a narrative tool could easily have felt trite, but it works brilliantly as a window into Austin's subconscious thoughts and a barometer of his deteriorating mental condition.

In his role as the endearingly awkward protagonist, Cole is extraordinary, displaying a brilliant precision that allows him to shift seamlessly from humour to pathos in an instant. With every little stammer and flub, he exudes a kind, gentle likeability that vitalises the show's emotional journey.

Each subtle detail contained in these 60 minutes is soaked with meaning. Tender, charming, yet quietly harrowing, Blank Tiles touches the heart many times over, before it crumbles, like Austin's mind, to a heart-rending conclusion.

Assembly George Square Studios, until 28 Aug, 3.55pm, £10--£11.