The poster for The Good Lie features a winsome looking Reese Witherspoon looking off into the distance while, beneath her, three Africans in tribal dress wander across a sun-bleached plain. But don't let the poster fool you. The film's real stars are the Lost Boys of the Sudan, who were the innocent victims of a brutal civil war that saw their villages destroyed and their parents murdered by the Sudanese People's Liberation Army. Forced to become soldiers themselves or face torture, the lucky ones who escaped walked thousands of miles in order to reach the Kakuma refugee camp in Kenya.

In Philippe Falardeau's excellent movie, this terrifying experience is re-enacted by four young boys and a girl (Peterdeng Mongok, Okwar Jale, Thon Kueth, Deng Ajuet and Kaje Jal) who, like the children in Slumdog Millionaire are brilliant at conveying the emotional anguish of the trek.

Once they reach the camp, where they spend the next 13 years, we see four of them grow into the actors Arnold Oceng, Ger Duany , Emanuel Jal and Kuoth Wiel, who are just as good and no doubt the realism of their performances is heartfelt by actors Duany and Jal who are from the Sudan and made the journey for real.

Eventually they are offered refuge in America which is when Reese the poster girl appears as a feisty Ms Fixit who finds them jobs, though not before they've learnt what to do with a phone or a McDonald's coke.

Their wide-eyed wonder in this new world is hardly surprising and I was reminded of the time I spent as a JC reporter in an Israeli absorption centre with rescued Ethiopians in 1985. They were fascinated by light switches and boiling kettles and the Lost Boys share that awe, though the film avoids dealing with any prejudice they may have faced and semi-sugar coats their work life.

This is a problem as Falardeau steers clear of schmaltz and makes you cry. The low-key performances by Americans Reese and Corey Stoll who plays her boss enhance the emotional impact.

In a week when almost 1,000 African migrants drowned while attempting to reach Europe for a better life, the unexpected timeliness of this great film is food for thought as the pre-election immigration debate rages on.