It is the band's first visit since releasing their debut album in 2012, with its long hazy explorations into the darker sides of the post-punk atmosphere.
That record was called Null Hour, denoting the beginning of a new period of time on which you will never look back, and a few hours have been put on the clock since.
The intervening years have seen a couple of band members added, and bassist/vocalist Ryan Harte stepping out from behind some effects-laden shadows on vocals.
''It's that density that I think we were lacking before,'' Harte says down the line from Auckland.
''That was the first noticeable thing.
''Our new guitarist, Dave [Provan], has a great character with his guitar. It's an almost infinite sustain, and he can do these really nice drones, layer up all these sounds that have melody as well, which just adds this really soundscape element to it. Luke [Kavanagh] can be charging away on rhythm, while Dave is just making these creamy layers on top.''
From the opening fuzz bass of Mirage, the mood of Glass is dense and claustrophobic.
There's a restlessness and repression churning throughout, like the flash of forlorn pain you get when you realise you have been walking in circles, feeling like there's no way through the fog, and the sad disquieting relief of a nihilistic outburst.
The palpable isolation echoes back to the group's writing process for the record.
''We went off to a hunters' lodge in the national reserve down below the Wairarapa,'' Harte said.
''We got the cabin-fever thing going, all four of us writing for a week before we went into the studio.''
The lodge in question is reportedly haunted, with a Fishnhunt NZ forum telling stories of lounge furniture moving itself across the floor at night, and mysterious figures appearing in the hall.
''I think we exorcised the place a little bit,'' Harte said, laughing.
''We had candles going, and it was a pretty spooky time. So we either brought the ghosts on or sent them away.''
Lyrically, Harte seems preoccupied with the optical. Ideas of vision and barriers preventing one from seeing stick out in singles Mirage and Clear, with the concept also refracting through to the album's cover: a classical sculpture hidden behind disorienting glass.
''The cover was looking at classical sculptures and how emotive they are with their dead eyes,'' Harte said.
''The concept of glass came up, a lot of the vocals either say that word or allude to something to do with that. It was a connection point between lots of the songs. And then there's also the glassy guitars on songs like Alt-figure. It made sense as a word. So that's where the glass-pane effect came from.
''The sculpture is the Head of Augustus. The head was part of a sculpture, which was decapitated by his successors and was buried under a temple where peasants would walk over it every day. It was done to say `this thing that you were cherishing as your icon, the power of your city, the peasants now walk over your head'. It's pretty heavy. It touches on the ideas of ego and vanity, which is cool.''
Sunken Seas play Chick's Hotel tonight.
