Debuted in 1999, Nikolaus Lehnhoff’s Parsifal has, in age, acquired something of the mythic sheen of the Grail itself. Returning to English National Opera after lengthy international touring, its legend arrived by way of vanguard — swathing the opening night in expectations and recollections. While Wagner’s final opera is generous in its harmonic warmth, inviting the listener in with luminous themes whose repetitions and reworkings invest them with welcoming familiarity, there is nothing warm about Lehnhoff’s production. The spiritual comforts of Christianity — the dove, the Eucharist, the resurrection — are all denied us here in this Beckettian, post-religious world.

The castle of Montsalvat becomes a forbidding bunker — a living prison for the dusty, shell-shocked relics that are the Grail Knights. A rock formation pierces the concrete wall, the natural universe forcing its way back into the hermetically sealed space of the chaste and — let’s face it — disquietingly bigoted Knights. Conceived in the wake of the first European exhibition of the Terracotta Army, the grey figures (who in Act III appear half-buried in a pit, wrapped in winding sheets) carry overtones of the misguided ambitions that begat their clay fellows. All of which has rather significant impact on the opera’s close. A railway line, a steel path curving out of view, leads Parsifal back to Amfortas and his company (now clad in Second World War uniforms of ambiguous nationality) but eventually also leads Parsifal and a far-from dead Kundry away, abandoning the Knights to their fate. Where does the track of single-minded faith lead? To Auschwitz? That certainly seems to be Lehnhoff’s suggestion.

Mark Wigglesworth in the pit plays a long game, shaping each act as a single musical trajectory, leading (as unequivocally as any railway line) to the Good Friday Music. He is aided in his narration by a cast of serious quality. Back in the money-notes of his bass register, John Tomlinson brings all his vocal stature and experience to Gurnemanz. He is balanced by the more flexible vocal colours of Iain Paterson’s Amfortas (strongly sung, but overdoing the dramatic histrionics). A solid Kundry from Jane Dutton never really catches fire; cruel direction moors her in a chrysalis far behind the proscenium for most of her Act II narrative. Stuart Skelton’s Parsifal by contrast, is all power and flame — a miraculously sung, if slightly inscrutable saviour.

Barring a couple of dramatic missteps (Titurel’s grinning death-mask greatest among these) Lehnhoff’s production is still a joy. Treating Wagner’s most domatic of plots to a wilfully oblique interpretation loosens the opera’s less palatable ideological armoury, allowing its music to breathe freely.

Further performances until March 12. Tickets: 0871 911 0200 (www.eno.org).