Dirs: Keith Fulton, Louis Pepe. UK. 2001. 89mins.

Lost In La Mancha is an enormously entertaining and poignant antidote to the bland "making of" films usually found as DVD add-ons and television plugumentaries. Instead of the traditional gushing interviews with cast and crew, this is the chronicle of an unmitigated disaster: the spectacular collapse of Terry Gilliam's ambitious decade-long dream of making the story of Don Quixote. It's a film equivalent to Final Cut, Steven Bach's book about Heaven's Gate, and also destined to become a classic of its kind. Brilliantly put together and benefiting from the valiant co-operation of Gilliam (who was in Berlin to support the film), this detailed and candid documentary can expect a raft of festival bookings and TV sales, and possibly some limited theatrical life as a specialist item.

Keith Fulton and Louis Pepe previously directed The Hamster Factor (1995), about the making of Gilliam's Twelve Monkeys, and named after the director's obsession with the antics of an insignificant hamster among his gargantuan and detailed set. The pair were then invited by the director to make a film about his new project, a $32m production called The Man Who Killed Don Quixote, starring Johnny Depp. They joined the crew in Spain eight weeks before the start of the shoot in September 2000.

It soon became tragi-comically obvious that, instead of recording the film getting off the ground, they were observing it going down in flames. Already under-budgeted, the production suffered a severe body blow two days into filming when the sets were destroyed by freak flash floods. Then Don Quixote himself, played by the septuagenarian French actor Jean Rochefort, developed a severe ailment, later diagnosed as a double hernia, and disappeared to Paris for medical tests.

By the sixth day, matters had descended into black farce, as a group of excited investors arrived, swiftly followed by (and carefully kept apart from) a band of insurance assessors and completion bond representatives. The production closed down shortly afterwards, prior to a $15m insurance claim.

Interviews and fly-on-the-wall footage are spiced with fragments of camera tests and rushes, as well as some magical sequences bringing Gilliam's storyboards to life and a brilliant Pythonesque resume (animated by Chaim Bianco and Stefan Avalos) of Gilliam's roller coaster career. Crisp editing and Miriam Cutler's flamenco-inflected score keep the pace moving along nicely.

The film presents Gilliam, convincingly, if a little insistently, as a modern Quixote: a visionary battling against harsh reality. In one sequence he auditions stocky, pot-bellied Spanish peasants for the roles of three giants, and beams with delight as they stumble awkwardly around. "He sees things the rest of us don't see," a colleague remarks. Although there's an element of schadenfreude in following Gilliam's downfall (he jokes bleakly that he feels like Job), the saddest thing about the film is watching the light gradually going out in his eyes.

None the less, it somehow manages to end on a upbeat note. The closing credits end with the brief filmed footage of those three rampaging giants, which naturally looks wonderful. A caption announces "Coming soon." One hopes that, eventually, Lost In La Mancha will feature as a really desirable add-on to the DVD of Gilliam's finished film.

Prod co: Quixote Films
Eastcroft Productions, Low Key Pictures
Int'l sales: Tequila Gang
Prod: Lucy Darwin
Scr: Fulton, Pepe
Louis Pepe
Jacob Bricca
Miriam Cutler
Jeff Bridges