All change at the Unicorn Theatre where Tony Graham has done such a good job these last 14 years; he signs off with a revival of the Michael Morpurgo football show he first did four years ago - I recall watching it on Cup Final Day followed by the match itself on a big screen projection - and Purni Morell of the National Theatre studio moves into the hot seat soon.

Billy does slacken a little in the second half, but this play is a game of two halves in which a dear old Chelsea Pensioner - beautifully played by Dudley Sutton - confronts his past in the park, and on the battlefields of Europe, and ponders the future.

The memories of the old player are prodded by a young footballer, played by Sam Donovan, and dreams of standing in the Shed are mixed with those of playing at Stamford Bridge; the only problem with the play is that you never know if the young chap is the old boy, his own son, or somebody else completely.

There are a few sly references to present day players like Jack Wilshere and Tom Cleverly, and you sense old Billy doesn’t think all that much of them; but the play would be much tighter if it made a little more of these historical comparisons, and less of the new dispensation with glib evocations of Didier Drogber and Fernando Torres.

Morpurgo’s story takes us through two world wars and the changing spirit of the game. It’s a real treat to see Dudley Sutton registering the switches between old times and new, the contrasting eras of Stanley Matthews and Paul Gascoigne. The fact that one generation fought a war made all the difference. And Sam Donovan brilliantly suggests a world of natural talent and opportunity that still might never happen; the world of Billy the Kid is a fantasy, long-vanished world of football that can never be recovered.