Arthur Miller’s great moral witch hunt drama The Crucible is an unexpected opener to the summer season in Regent’s Park, but the power and glory of the play carries through a long, long evening.

Timothy Sheader has not directed the play as a musical, exactly, but his staging is certainly epic, from the minute we hear the singing of girls in long skirts and Puritan bonnets coming through the tall trees and taking up their choric posts at the side of a flat wooden stage, a horizontal house front.

These girls, recruited from the East 15 Acting School, are an essential element in the production, a worrying presence of semi-sexualised adolescence, attending to the dialogue, or turning their backs on it, and they have the gestural intensity of living sculpture.

Young Abigail Williams, spiritedly played by Emily Taaffe, leads a dissembling dance around the catatonic figure of a ten-year-old, the daughter of the Reverend Parris (Christopher Fulford), new to the community and trying to turn the tide of mounting hysteria and righteousness.

For although the play is ostensibly about the Salem witch trials of 1692, and was always taken to be Miller’s allegory of the hearings of Senator McCarthy’s House Committee of Un-American Activities, it grips like a vice in its study of moral panic, galloping gossip and the terrible consequences when individuals are blown on the wind of high-minded interference.

Sheader’s production carries this terrifying force, and ratchets up another gear when the pettifogging malice of the neighbours is taken up as a legal cause by the official delegation led by Oliver Ford Davies’ oh-so-oily deputy governor Danforth, and the play concentrates on the helpless tragedy in the marriage of the honest, flawed farmer John Proctor (Patrick Kane) and his wife Elizabeth (Emma Cunniffe), devastated by the tittle-tattle.

Some of the fourth act gets lost in the deepening night, but not too much, as Kane builds a tremendous histrionic performance, almost Christ-like, very different from Iain Glen’s powerhouse display in Dominic Cooke’s 2006 RSC revival.

This is a big moment in the history of the Open Air Theatre, and Sheader’s team – designer Jon Bausor, composer Nick Powell, and a company led by former RSC stalwarts Patrick Godfrey as a weather-beaten old Giles Corey and Susan Engel as a gloriously sensible Rebecca Nurse – rise to the challenge with ardour and magnificence.