Simon Fitzmaurice was a promising young filmmaker with a loving family and two award-winning short films under his belt when he received a devastating blow. In 2008, aged 34, Simon was diagnosed with Motor Neuron Disease, and was told he had three or four years to live. Now 42, the director has five children and has directed the film My Name Is Emily.

With Colin Farrell's narration adapted from the director's memoir, Frankie Fenton's documentary is powerful stuff. Farrell's voiceover is tender and intimate, capturing both Simon's struggles and his determination to persevere. The narration not only allows Simon to express himself, but also illustrates how beautifully and insightfully he does so. His writing is poetic, though not sentimental, with the prose effectively conveying the personal magnitude of his journey. Recounting the moment he received his diagnosis, he says, "Light leaves the room. And air. And sound. And time."

Fenton uses home videos and landscape shots to play with movement and stillness. He captures both Simon's physical deterioration - which leaves him immobile without the help of a motorised wheelchair - and the unrelenting momentum of his ambition. Moving his camera along train tracks and ocean waves, Fenton captures the bittersweet nature of Simon's incredible achievements. They're awe-inspiring, and finite. There will be an end. Simon is always aware that he may be doing something for the last time.

Interviews with friends and family are similarly conflicted, as Simon's wife Ruth expresses the utmost support and admiration for her husband, while also lamenting the losses that come with MMD. It's Not Yet Dark evokes the heartbreak and the inspiration of Simon's story, and the passion he has for creativity and life itself. "The best past of living with MMD is the living part," he says. "I love being alive."

8/10
It's Not Yet Dark is out now