Following in the tradition of the finest testimony-based theatre, Factor 9 gives the stage to the survivors of a 1980s pharmaceutical disaster in which thousands of people worldwide became infected with the HIV virus after taking factor 8 and factor 9 blood products for haemophiliacs. The play, scripted by Hamish Macdonald, is directed by Grid Iron’s Ben Harrison, who returns to Dogstar after his successful collaboration with Matthew Zajac on his fact-based piece The Tailor of Inverness.

Zajac is joined on stage by Stewart Porter, but the real coup this time is provided by highly sophisticated set, video, and lighting design, courtesy of Emily James, Tim Reid and Paul Claydon respectively. This world, made up of plexiglass, carefully frames evocative imagery and is subtly underscored by Pippa Murphy’s music, and even opens up at one unexpected moment to reveal its viscera – a wall made up of hanging blood bags.

Revolving around the members of the so called Edinburgh Cohort, Bruce Norval and Robert Mackie, Hamish Macdonald’s text is research-heavy but nevertheless painstaking and steadfast in its reverence for the victims of the scandal. Managing to pull out and focus on the more poetic content of the play – Bruce’s dreams, or imagined telephone conversations between anonymous authority figures keeping the tabs on the death toll – Harrison paces the stage action with great technical skill and inspiration. Zajac and Porter too are a complementary double act combining thoughtfulness with temperament and finesse with feistiness. Harrison’s stated goal in his programme note – a call for a true dialogue born out of a deep respect for the NHS – is disarmingly honourable too. The overall effect of this ambitious work is deeply touching on many levels, although one wonders whether a more economical and focused approach to the narrative might have yielded a more lasting piece of theatre.