As striking as Unloved's mix of '60s pop and cinematic mystique was on Guilty of Love, at times their debut album felt like a soundtrack in search of a story -- which isn't surprising, considering that two-thirds of the band are respected composers for film and television.

In BBC's spy thriller Killing Eve -- to which they contributed Guilty of Love tracks as well as a virtual album's worth of previously unreleased music -- David Holmes, Keefus Ciancia, and singer/songwriter Jade Vincent found their perfect project.

The show and its brilliantly unhinged hitwoman Villanelle reflected Unloved's postmodern femme fatale vibe perfectly, and allowed them to push their boundaries with mercurial tracks that made the most of their seductive, dangerous sound.

Unloved's evolution continues on Heartbreak, an album that presents the most skillful balance of their pop and experimental sides to date.

With savvy, they kick things off with some of their catchiest songs.

The title track is a master class in déjà vu -- not only does Unloved capture the poignant grace of '60s girl group ballads with uncanny skill, the songwriting is so tight that it feels like it must be a forgotten classic.

"Love," a show-stopping concoction of tribal drums, brass, guitars, and marimba, hints they had a lot more fun making this album than they did Guilty of Love.

This playfulness extends to more radical moments like "Fail We May Sail We Must," which features one of the heaviest and spookiest uses of phasing in a pop song in the 60 years since Toni Fisher's "The Big Hurt," or "Devils Angels," where droning electronics streak like race cars around Vincent's knowing vocals.

Indeed, Vincent's voice is as much of a special effect as any of Holmes' or Ciancia's sonic wizardry.

She's the star of Heartbreak as well as its anchor, grounding its freewheeling sounds with the depth of her performances.

Like Unloved's other members, Vincent is well-versed in pop history, evoking Amy Winehouse, Dusty Springfield, and Burt Bacharach's divas as she disappears into the characters that populate Heartbreak.

She teeters between sultry and scary on "Sigh" and "Crash Boom Bang" in a way that will please Killing Eve fans, but widens her range to include world-weary desperation on "Danger" and tear-soaked betrayal on "Bill." While Unloved's pastiche of ultra-hip influences could easily be too mannered, the emotional honesty of songs like the haunting finale "If" makes Heartbreak a near-perfect union of style and substance from a group growing by leaps and bounds.