JOHNNY “ROOSTER” BYRON is an unlikely saviour. He is a drunk, a drug dealer, a deadbeat dad, and a foul-mouthed philanderer. Yet, to the teenagers who congregate around his caravan, pitched on woodland by a new housing estate, he offers refuge from difficult home lives, non-stop parties, and a link to “St George and the lost gods of England”. Jerusalem opens with a dazed Eleanor Worthington Cox in Titania wings singing Blake’s hymn, jump-cuts to the rave the night before, and then reveals the morning after, as two council officials serve an eviction notice.

From these first few minutes, the play’s battle lines are drawn between the language of modernity — the officials announce themselves as representing “strategy and partnership” — and the earthy expression of Byron, anchored in a more soulful past. Having seen off his tormentors by barking through a megaphone, Mark Rylance’s entrance is magnificent, his arched back and bow legs grooving to a blues record, before he does a handstand in a water barrel, and mixes eggs, milk, and vodka into a hangover cure. Front-stalls audience members get to keep the shells and milk bottles as a souvenirs.

Rylance’s theatricality never falters for a moment of the three-hour production, as he extracts gas lighters and hip flasks from his cargo pants, or tea trays and a mitre from his caravan. The mitre is for Alan David’s Professor, a linen-suited eccentric who narrates both the folkloric traditions surrounding St George’s Day and the saint’s conversion of Cappadocia.

While the younger characters make no reference to the Professor’s theological explanations, Tanya (Charlotte O’Leary) does read with great ceremony the Irish blessing “May the road rise up to meet you” for Lee Piper (Jack Riddiford), “a man of this vale”, who is flying to Australia the next day.

Not all of Byron’s ceremony-making is positive. He initially repels his nemesis Troy Whitworth by reminding him of how scared he had been by youthful, possibly satanic, rituals. But, by the time that memories of long-ago satanism are invoked, it is too late: Byron has learned that his acolytes have betrayed and defiled him in the most horrible way.

The betrayal brings to the foreground Byron’s relationship with MacKenzie Crook’s Ginger, on the surface a live-and-let-live Everyman, whose greatest ambition is to replace the Two Trevs as DJ in the Cooper’s car park for the annual Flintock Fair. But Byron omitted to tell his closest friend about the previous night’s party, and Ginger does not put himself in danger when Whitworth’s thugs return for Byron.

Reviving Jerusalem ten years on, with a now 62-year-old Rylance and 50-year-old Crook, darkens the question what these men are doing spending so much time with teenagers. Are they avuncular mentor figures, or something seedier? The play’s conclusion hinges on the latter interpretation, when Byron’s broken body is tortured further for sheltering Whitworth’s runaway stepdaughter Phaedra.

Phaedra was the singer of “Jerusalem”, the jittery spirit seeking sanctuary in a woodland glade filled with rubbish and old car seats. “Come, ye giants,” Rooster pleads at the end, alone and praying for a higher power to save him from humanity’s basest instincts, and modernity — which may, or may not be, the same thing.

Jerusalem by Jez Butterworth is at the Apollo Theatre, Shaftesbury Avenue, London, until 7 August. Phone 0330 333 4809. jerusalemtheplay.co.uk