Tony Graham's touching adaptation of Michael Morpurgo's story about a forgotten Chelsea football legend is back at the Unicorn theatre. With the same cast that won the hearts of even rival football fans four years ago, it's the tale of an old man recalling a brief career at the club - cut short by World War II.

But it's also the tale of his grandson, who is going for a trial at Stamford Bridge and struggles to credit the old man he calls Uncle Billy.

Even if you have no love of football and still less of Roman Abramovich's pet club, have no fear: this being a Michael Morpurgo story it's much more about emotional bonds than it is about inflated egos kicking around inflated leather. And like other Morpurgo stories, it's rooted in World War I, with Billy's own father dying from the effects of mustard gas.

Billy's journey then takes him from scoring at Stamford Bridge to serving in North Africa, becoming a POW in Italy, to witnessing the horror of liberating Auschwitz - before winding up supping cheap lager on a park bench.

Although the ending is too easy, this is an absorbingly emotional yarn, rooted by Graham in feisty dialogue. Graham's production also sticks to two actors and deftly weaves together themes of age and youth, reconciling past and present.

Adam Wiltshire's set of a mangy London park is strikingly lit by Phil Clarke and Sam Donovan is hugely versatile as the young lad and sundry other characters. Donovan also has great rapport with Dudley Sutton, who gives a thoroughly engaging performance as the older man revivified by memories of youth. It's enough to make you root for Chelsea.
 

Fun with football before the show starts may give the impression that this piece is about football. It isn’t, of course. Michael Morporgo’s stories return repeatedly to the futility of war or the hard lot of animals - both in the case of War Horse - and with Billy the Kid we’re in classic Morpurgo territory. A poignant but up-beat story about a talented young Chelsea footballer whose life is wrecked by the 1939/45 war. it is also a powerful, and often funny, look at how the very old and the young relate to each other.

Dudley Sutton develops the character of Billy from a drunken tramp sitting on a park bench to an upright Chelsea Pensioner returning to “his” home football ground as a guest of honour - via the telling of his story in flashbacks. We see him as a football kicking schoolboy - prisoner of war in Italy, burying concentration camp dead, incurring a life-changing injury and returning to post-war pointlessness and homelessness. Sutton’s impeccable acting and evocative harmonica playing brings the youth of his character to life but always realistically through the old man’s memories.

There’s excellent work too from the versatile Sam Donovan who plays all the other parts - including the troubled Sam who is Billy’s scornful, insecure young listener, an RP speaking army doctor, a hilarious Italian referee and a Liverpudlian policeman.

This is Tony Graham’s last show for Unicorn, whose new Artistic Director Purni Morell is now in post. Billy the Kid, an imaginative reworking and updating of Unicorn’s 2007 version, is a fine show to go out on.

Sam is a know-it-all teenager who dreams of the celebrity and big wage packets of professional football as he kicks a ball around the local park and boasts that he has been signed up by the Chelsea Academy. Billy - a broken-down, smelly heap of a man who sits in the park with a beer in his hand - has actually played for Chelsea: in the 1939 season he was the sensational teenage striker known as Billy the Kid. But the war brought an end to his hopes of fame and glory, and now all Billy has is his memories and the possibility of teaching Sam a thing or two, if only the lad would listen.

Tony Graham takes liberties with Michael Morpurgo's children's novel, but scores with a 90-minute show that wears its football lightly. The young audience members get the chance to take some goal kicks before the show begins, but while the piece captures all the thrill of a big match day, this is as much a tale of lives shaped by war and the merciless march of history as it is about football. It skips lightly from the famous Christmas Eve match between German and English soldiers in no man's land, through the second world war and the liberation of Belsen, to the present day.

This is a softly spoken play that doesn't thump its messages home, more reflective than rowdy as past and present, young and old rub together and create friction. It boasts two wonderfully fresh performances from Sam Donovan as the youngster and Dudley Sutton as the grumpy old codger whose ears still ring with the roar of the crowd.