2010's Kiwi wunderkinds The Naked and Famous set themselves a daunting challenge with their debut Passive Me, Aggressive You. A synthpop first-outing as well-rounded and thoroughly stunning as it is is a difficult feat to top, combined with two solid years of relentless touring, and you've got yourself a potent concoction sure to induce the dreaded sophomore slump.

C'mon, in all honesty, how could they beat 'Young Blood'? It may have been plastered across indie-discos, Skins, Arcadia-owned fashion outlets and tweeny-boppers nationwide, but that doesn't stop it being an utterly fantastic pop anthem. From the moment those keys tremble into life to the moment frontlady Alisa Xayalith croons her last angsty refrain, it's a delirious adolescent cyclone.

Amongst the dense shrubbery of summer releases and a tight fall schedule, the New Zealand quintet unleash In Rolling Waves. They've already teased the long-player via lead single 'Hearts Like Ours'. It's a fluttering fusion of jumbo pop hooks and searing dreampop; synths, embroiled with indie-rock guitars, beat ceaselessly against club grooves. The track is essentially 'Young Blood' transplanted into second album territory - it's similarly magnificent and bears a chorus blueprinted for high-octane singalongs: "Half awake and almost dead/ keeping empty beds elsewhere/ we're yet to bleed, we're yet to bleed/ all the time and energy."

The majority of the record exacerbates a style glossed over during Passive Me, Aggressive You. Many tracks exceed five minutes - this is a hefty release, clocking in at almost an hour - and, with resemblance to 'Spank', 'The Sun' and 'Frayed', feature intertwining strands or layers that expand into the horizon. What may start as a fragile ballad or basic pop melody in the end becomes a sprawling post-rock-structured opus. 'A Stillness', for example, begins life as a jaunty '60s-tinged acoustica number, before evolving into a mechanical dreamrave vortex dripping in Crystal Castles-ish distortion and a throbbing pulse.

A lot of the album feels less reliant on massive riffs. There are indeed still gleaming hooks and infectious earworms, and there's still a synthpop sheen that washes over each segment of the album, but rather than the bombast of 'Girls Like You' or 'All Of This', things are more often than not dialled back. 'Waltz', with Grimes-style synths and a disco beat ventures into an almost gothy/noiry electronica region; things don't get dark enough to really warrant 'goth' per se, and there's glimmering tropical arpeggios which aren't exactly Sisters Of Mercy, but The Naked and Famous do drop their usual blithe pep down into a pit of wayward despair, apathy and disconnection. Even the broodier moments on their debut were kept afloat by an undercurrent of hope, whereas In Rolling Waves seems to incite a seething fury instead.

On the whole, this album is everything we could've hoped for. It's fundamentally a sequel to their first LP - things are more adult, darker and more realistic. Musically, they've got the cojones to veer away from pure pop and dabble in more experimental territories, utilising structure, dynamics and texture to impressive effect. Plenty of the twelve songs on the album are sublime: 'The Mess' is a haywire chip-pop ballad, 'A Small Reunion' is an awe-inspiring hodgepodge of violins and duelling vox, 'Golden Girl' is serene like dawn on a transatlantic flight, 'We Are Leaving' employs the broken neons of Kiss Land, gothspel choirs and panic-attack percussion. It's difficult to find faults.

The only true misstep is how uncannily alike the chorus of 'What We Want' and Cutting Crew's 'I Just Died In Your Arms Tonight' are. Not because it's a bad thing really, but just because it's so glaring and distracting.

In Rolling Waves doesn't have the same grab-you-by-the-lapels instant gratification nature as Passive Me, Aggressive You. It's not bubbly gung-ho pop centred on youthful anxieties and romantic foibles. It's a more world-weary anthology, quite content to take all the time in the world to make a statement - and don't be fooled by the meandering, because boy do they get there. Some may not take the time to get to grips with all this has to offer, and if it's just a Topshop OST you want, 'Hearts Like Ours' will fill your Naked and Famous quota.

For others willing to explore and be led on tangents, this will be a perfect record to be absorbed by. There's a great many treasures to discover by just sitting and listening. Don't dismiss them as 'that band off Skins', as they've grown into so much more.

If their debut was a coquettish pair of flickering eyelashes and a set of flirty, pearly whites ready to lure you over, In Rolling Waves is the muscle you can feel ripple. It's the hot gasps, the goosebumps, the damp hair to be tangled in and the fingers brushing against your spine. Let it take you.