Crystal Castles, Heaven, London

A sparkling duo at their feral best

Crystal Castles might be huge with the world's club kids right now – just see this month's cover of Dazed & Confused magazine – but their exhilarating and terrifying sound isn't for the faint-hearted or uninitiated.

Since their emergence from the Toronto underground with their first album, Crystal Castles (a surprise 2008 smash hit selling 200,000 copies), their menacing electro beats and rippling vibes have generated enough NME hyperbole to pack a convoy of tour buses.

Thankfully for the electro hipsters crammed into London's Heaven club, their spaced-out keyboards, intimidating vocals and pounding bass defy fears that they may have gone soft with the release of their second album (confusingly also self-titled) after a two-year break and inking a major record deal.

"Fainting Spells", the first track from their new album, is frantic, more than a subtle nod to their formative years on the Toronto punk scene. Its glitchy wails and squawking hisses are menacing, testing the small venue's sound system to the limit.

Alice Glass, the Canadian duo's singer, is mesmerising, almost feral as she surfs into the crowd. While "Baptism" sees her scale the band's drum kit, thrashing cymbals and towering over the band before she's back among her frenzied fans for a nightmare-laden take of their first album's "Courtship Dating".

"Doe Deer", also off the new album, is pure Crystal Castles; Glass full of rage, her vocals barely decipherable over band-mate Ethan Kath's 8-bit assault on the senses. "Celestica", the band's great new single, is a set changer, its deep warping beats and otherworldly feel bringing a note of calm, its lyrics in part borrowed from Delerium's "Silence" ("Do you pray with your eyes closed... When it's cold outside, hold me tight, hold me"). But its respite is only fleeting as Glass – stationary on the stage for the first time in the evening – is flung back on to the crowd by the blistering beats of "Empathy", illuminated in the pitch-black venue only by the glowing camera phones held aloft by her fans.

The Ontario pair are electric on stage as the strobe-heavy set reaches its climax, but it's Kath, the band's multi-instrumentalist and producer, who is the real musical talent, laying down hard, intractable digipunk for Glass, alternated with moments of euphoric, tripped-out transcendence for an audience gasping for breath.

"Crimewave" and "Air War", two big tracks from their first album, are real crowd-pleasers, introducing an element of Kraftwerk-like Euro-pop to the evening, before the frantic vocals of "Untrust Us" and the rushing electro sounds of "Intimate" send the crowd into a frenzy and fans lunge forward, desperate to be part of the swaying beast sliding Glass back and forth across the venue.

As they close it's clear their set, like their new album, is without structure. But this is their brilliance; they rise and fall with tight sound and varied tracks, demanding attention while forging no narrative. And in the end it's this awkwardness – this mix of frenzy and transcendence – that leaves the crowd spellbound, sure they've become harder, faster, more anthemic and more terrifying in their absence.