In the scientific world, antibodies identify and neutralize foreign objects in our bodies, fighting off bacteria and viruses and duplicating the pathogen to better combat future illness. In the case of Nate Kinsella's project Birthmark, whose third album and Polyvinyl debut is named after the immunoglobulin, the word takes on a new meaning, suggesting the feeling of self-loathing or disconnection from one's own skin. That sort of emotion is ripe for the creative picking, but if it's an accurate assessment, Kinsella should take it easier on himself; with Antibodies, he's not only at his most personal and sincere, but his surprising fusion of electronic, orchestral, and post-rock elements finds him following his muse and shifting the spotlight away from his more attention-getting cousins Mike and Tim (Cap'n Jazz, Joan of Arc). Antibodies is fascinating, layered and unpredictable, playing Kinsella's confessional lyrics against Jekyll & Hyde strings, propulsive percussion, and angular pop melodies. Opener "Stuck" is anything but, as mischievous vibraphone and driving electronic drums carve a path for pastoral woodwinds and fluttering keyboards. Those drums help make the transition to "Shake Hands," which seems straightforward enough but reveals a centerpiece of strings played on a backwards loop, simultaneously funky and disorienting. If "Shake Hands" is disorienting, "Please Go Away" is paranoid, as electronics glitch, drums stutter, and Kinsella's distorted vocals ask questions like "Is my destiny without a destination?" The last half of the record takes a gentler turn, quelling the earlier storm of sounds and making Kinsella the more obvious focal point, as on the shimmering "Your Imperfections," where he compares the ugliness of his faults to the beauty of his wife's flaws. On second thought, if Antibodies is the result of putting self-loathing to music, it may be bad for Kinsella personally, but it serves him well creatively.