It's 1940, and musician Katy Green gets what ought to be a dream gig, playing with the Ultra Belles, an all-female swing band. They travel by Pullman on the luxurious Starlight from Los Angeles to Santa Cruz, Lake Tahoe and San Francisco. So what if the songwriter is Katy's ex-boyfriend, and a notorious Casanova? So what if half the women are mad at the other half over politics, music, and sex? There are tensions and rivalries in every band. But that's not the worst of it. Katy quickly discovers that somebody's out for blood.