Omaha, Nebraska post-emo outfit Cursive are no strangers to concept records.

In 2000 they released Domestica, a deeply troubled album of raw-nerve post-punk with themes of divorce and infidelity running throughout.

Their 2003 release The Ugly Organ followed the sexually depraved exploits of a depressed organ player.

Nine years later, I Am Gemini gets a little deeper conceptually with the surreal story of Cassius and Pollock, twin brothers separated at birth.

It's a wild and fiery tale that, in the hands of bandmembers with less than 15 years of playing together under their belts, might quickly turn into fantastical goop.

In Cursive's case, however, the concept is kept in check by the band's deft compositions, each song weaving angular guitar riffs with catchy bridges.

Singer/guitarist Tim Kasher sings like a less sedated Jeff Tweedy in some bizarre carnival barker role as he delivers some genuinely out-there lyrics throughout the album.

Kasher's themes return often to images of polar opposites -- angels/devils, sun/moon, halves and other gemini-referencing tropes -- but without a press release to let you in on the concept, a lot of the songs are nebulous enough to just sound like convoluted breakup fare.

Then we get something like "Twin Dragon/Hello Skeleton" spinning out of control with lyrics like "I am the holy second coming!" and "What would that poor coward say if only he'd seem this way?/Maybe he'd finally behave more like a man should behave...maybe less like a nun." If you're not reading along with the liner notes, the narrative gets a little messy.

A chorus of angels comes in to help clear things up on "Wowowow," courtesy of a heavenly host of backup vocalists.

It's a beautiful effect, but ultimately sheds no light on what's transgressing.

Gorgeous instrumental vignettes like "Lullaby for No Name" and "This House a Lie" make I Am Gemini feel more like a soundtrack than any easily read linear story line.

This all becomes secondary to how colorfully and enthusiastically the songs themselves are performed.

The bombastic math rock-pop of "Drunken Birds" explodes out of the speakers in a rainbow of guitar and synth tones snaking around echo effects and an always changing song structure.

Much credit is due to producer Matt Bayles (who has also worked with Mastodon, Minus the Bear, and other heavy-hitters) for compartmentalizing some of the more unwieldy elements of Cursive's ever-morphing output.

Concept or not, I Am Gemini is a winding ride, relentlessly shifting musical gears as it spits out a manic tale of a battle between the good and evil twins.

The dynamics of accessible songwriting mingling with weird breakdowns and abrupt production jumps make sure the songs are always engaging enough to keep the listener riveted, even when the saga of the twins starts to lose the plot.