The best stories are always the true ones and anyone questioning why documentaries are entered in the film festival may question why we bother with fiction after viewing the unforgettable Fighter.

It tells the story of two Czech Jews who return to their old Second World War haunts.

Let me declare an interest at this point. My grandfather spent three years fighting in the front line in the First World War.

He came home with a rich line in anecdotes, songs, jokes, poems and observations with which he would entertain his children and later his grandchildren.

Every time a different story -- a living, walking, breathing history which could fill a book.

Every time we listened and said to ourselves and each other: "We really must record this before it's too late.'' And pretty soon it was too late and an entire fascinating chapter of history was lost leaving me with an empty guilty feeling that a whole legacy had been squandered.

That's why Fighter is precious -- it's a gripping true tale immortalised.

After the Munich sell-out which left Czechoslovakia practically defenceless to the Nazis Jan Wiener left Prague with only the clothes he was wearing to find his father in Yugoslavia.

He then held his father's hand as he committed suicide rather than let the Nazis take him as they closed in on Belgrade.

His German Aryan step-mum took her life at the same time choosing to die with the man she loved rather than walk away and save her skin.

Back home his mother was beaten to death in a concentration camp.

But Wiener wasn't going down without a fight. He vowed to reach Britain and join up with the free forces to wage war on the Nazis.

Clinging to the underside of a train, Wiener made a bid to cross Europe before being captured by Italian military police in Genoa.

He escaped and by 1943 was in the Royal Air Force blitzing the Nazis.

Meanwhile Arnost Lustig was forced to build railways at a concentration camp.

The rails for him conjured up romantic fantasies of travel and freedom.

After the war he learned that track led directly to Auschwitz.

You might think all this would make for an oppressively sad movie but far from it.

Wiener and Lustig get drunk and talk about women in a variety of bars. They joke and bicker in the manner of Walter Matthau and Jack Lemmon in the Odd Couple.

At times it's like a good road movie as they traverse Europe.

Of course the humour is black. In Italy Lustig says at one point: "There were 2,000 Italian deserters here. They were the best people in the world.

"They were told not to flirt with the German women or they would be hanged.

But they did and they were hanged every night.

"But nobody can stop Italians from flirting with women.'' But Lustig's sunny nature is an irritant to Wiener, who is the Fighter of the film. Experiences like his leave indelible scars.

The pair fall out over Lustig's Communist past. The same communists who stole Wiener's house and jailed the returning hero for five and a half years for nothing.

Jailed by some of the same people who had done nothing when the Nazis marched.

As Arnost puts it: "Wiener is a hero in a time when there were millions of cowards, millions of people who were indifferent. In this time Wiener became a fighter.'' Further on in their trip the pair row again and filming stops. We never get to here about how Wiener got to England and what he did in the RAF.

Instead you are left with half the story, craving more.

But director Amir Bar-Lev should be proud. He made the effort.

And unlike me he won't be saying to himself years from now: "Mmmm. There's a good tale. One of these days I really must make a film about it before it's too late.'' The Fighter is showing today at 3 p.m. at the Liberty Theatre and on Monday at 6.30 p.m. at the Liberty Theatre.

BIFF MOVIES MPC