Quicksilver Theatre at Boilerhouse Theatre, Stoke Newington, London

There is always a greater picture” is the mindful message of Quicksilver’s new play for over-sevens by Diane Samuels, inspired by 13th-century French and German children’s crusades.

Guided by the Sun, the play’s hero and heroine Leo and Grace are on a starved, parched quest to join the flag-waving army of “innocent” children led by Sheep Boy to save sacred Ash Mountain from evil others promoting plague, famine and strife: the Great Liars.

Their squabbling journey illuminates the ominous consequences of fundamentalist certainty (including Christianity) and wilful, political expediency that here asserts the Sun over the Moon via “an army of peace, not war”. For sloganising Grace, trudging to avenge the gory murder of her father, “there are bigger things than fairness and staying alive”. What use are you dead? asks wide-eyed Leo. Immersed in Moon rituals, Poppy warily treads a middle path.

Sombre, graphic imagery (gruesome murder, a rampaging army “carrying truth with clubs and knives”) - is leavened by Steve Byrne’s racy song, and flashes of mordant humour. The pragmatically thuggish Pigface is played by Roy Weskin with the sly gusto of a Breughel gargoyle.

Echoing horrors of Nazi Germany, Bosnia and erupting New Rightism, the play contests the need for saviours and heroes. “Whose light?” is the burning question.While its determinedly poetic symbolism needs clarifying input from teachers (an accompanying programme playscript helps), its clarion call for a broad church is pressing.

One Hundred Million Footsteps (with programme playscript) runs at Union Chapel, Islington, London N1, July 7-19, preceding an autumn tour. Tickets: 0171 241 2942