Apples are an abiding force in the tales which people tell – from the temptation of Eve through the judgement of Paris, Atalanta’s race and the Hesperides down to folk myths from across the breadth of Europe. They are a comforting fruit, capable of many uses, and their longevity must have made them even more important in the long winters when icy winds blew across from the east.

So apples become a potent symbol in Trestle’s new piece of physical theatre. The Glass Mountain is a Polish legend about a wilful princess imprisoned by her parents at the pinnacle of the high slippery slope which gives it its title; writer Anna Reynolds has drawn on the stories of the St Albans Polish community for her plot and dialogue. Emily Gray’s direction owes much to the work of Polish physical and vocal theatre companies with which Trestle has collaborated – Teatr Piesn Kozla and Gardzienice.

A corona of gleaming apples glistens above the acting space, which Katherina Radeva has furnished with a variety of step ladders and chairs. The legend itself is intercut with the stories of economic migrants as they journey to England. There’s the father who knows that the money he sends back home doesn’t really compensate for his absence as his children grow up. And the mother who wants to surprise her middle-aged son (not to mention his male partner). A young woman has her life in London as smartly mapped out as her own colour-coordinated outfit. While a young man is torn between proving himself to the girl whose parents think he’s not good enough for her and his need to be with her – now. Some of the dialogue and the songs which carry the action forward are in Polish, but that doesn’t make the story difficult to follow as it is also conveyed through movement and dance. Much of the singing has the deliberate rough edge which authenticates actual folk-song; Laurence Kaye is the musical director. The movement involves all the ladders which take on their own parts in the drama and Radeva has devised some simple but effective costume changes to indicate the shifts from the present day to a timeless past, which may also be the future.

The four players are Lenka Rozehnalova as the young women. She’s moving as the princess waiting for rescue, watching the failures and knowing that time rushes by. Kate Lush contrasts the naïveté of the modern mother with the ruthlessness of the queen with her eagle alter-ego. Olek, rushing ahead with his plans without really considering how they affect other people, is played with wide-eyed intensity by Jacek Wytrzymaly and Sean Garrett gives weight to the husbands and fathers who want to do what is right, but know that there is a price to pay.