Natasha Khan's debut album as Bat for Lashes, Fur and Gold, was so vivid and fully realized that it was a tough act to follow: she found ways to make her wildest flights of fancy into music with the immediacy of pop and the intimacy of a singer/songwriter's confessions.

It takes a lot of ambition to pull off that kind of alchemy, and that ambition defines Two Suns.

Khan's sounds and visions are even more widescreen here, full of pristine electronics and heady concepts, and Scott Walker, the undisputed king of high-concept music, duets with her on the ultra-theatrical finale "The Big Sleep." Since Bat for Lashes' songs practically burst with characters and ideas, a concept album seems like a logical next step for Khan's music, but the magic her songs had previously feels dissipated this time around.

Two Suns revolves around Khan's "desert-born spiritual self" and her "destructive, self-absorbed, blonde femme fatale" alter ego Pearl as it covers "the philosophy of the self and duality, examining the need for both chaos and balance, for both love and pain, in addition to touching on metaphysical ideas concerning the connections between all existence." That's a lot to pack into just 11 songs, and it's not always entirely clear just what they're about, despite motifs like "blue dreams" that run through them.

Some songs are just plain overdone: "Traveling Woman" and "Peace of Mind," with its tribal rhythms and gospel choir, aim for majesty but end up dragging.

Others use the album's posh polish to make an impact, like "Glass" -- on which Khan hits some amazing high notes -- and "Daniel," which nods to the poppier side of her music.

The directness that made Fur and Gold's modern-day fairy tales so enchanting and moving is often missing, and nothing on Two Suns is as musically or emotionally immediate as "What's a Girl to Do?" or "Sad Eyes." However, the subtler spells Khan casts with hypnotic tracks like "Sleep Alone" and "Moon and Moon" eventually reveal their beauty.

And as Two Suns unfolds, it gradually shifts from overt attempts to dazzle listeners to focusing on Bat for Lashes' greatest strengths: Khan's voice and her considerable skills at telling a story and setting a mood.

Pearl may be the album's dark side, but she's responsible for some of its best songs.

"Siren Song" sets her seductive false promises to dramatic pianos, while "Pearl"'s Dream," with its battles and kingdoms, is classic Bat for Lashes.

"Good Love" reaffirms Khan's way with bruised ballads, and "Two Planets"' pummeling beats and swirling voices make the mystical power the rest of the album reached for crystal-clear.

Ultimately, Two Suns is nearly as graceful and poetic as Bat for Lashes' best work; it's just that the album's massive concepts and sounds require a little more time and patience to unravel to get to the songs' hearts.

It's clear that Khan's talent and ambition are both huge, and for her to slightly overreach is better than not aiming as high as she can.