Revered Brisbane prog-rockers Caligula's Horse will follow up their lauded 2015 album Bloom with their fourth studio full-length this year, and have announced its September release today.

Titled In Contact, the creation of the record was "an enormous proposition", frontman Jim Grey said in a statement, full of "deeply personal" songs.

"We've never been more excited to share a new work with the world," he said. "The sounds on this album are dark and adventurous, but without losing the bittersweet and joyful sounds we developed in writing Bloom."

As with its predecessor, the songs on In Contact bear the fruits of Grey and guitarist Sam Vallen's fertile creative collaboration, a process in which "every idea is scrutinised, deconstructed and rebuilt in a way that one of us, alone, could never achieve", Vallen said.

"We're one another's harshest critic but, fortunately, we've done this for long enough now that our inspiration draws us in a similar direction — we can finish each other's musical sentences, so to speak," he explained.

"And we're lucky that's the case, since In Contact proved to be a much more ambitious undertaking than anything we'd conceived of in the past."

That undertaking spanned several months between late 2016 and May this year, during which the 10-track album was written, before swiftly being laid down in the studio over May and June. The album echoes 2013's sophomore full-length, The Tide, The Thief & River's End, in that both are concept albums, though Vallen indicates that In Contact comes "from a more personal place" than its elder sibling.

Caligula's Horse are just about to embark on a European tour, comprising support slots for Opeth, Anathema and Pain Of Salvation, as well as a run of headline UK shows and festival appearances in Spain and the Netherlands. That tour comes in conjunction with a reissue release of both The Tide, The Thief & River's End and the band's 2011 debut, Moments From Ephemeral City, out on Friday 16 June via Inside Out Music.

The group wrap their international stint on 30 June, so keep your eyes peeled for news about their return home and consequent movements in the lead-up to In Contact's release on Friday 15 September through Inside Out.