S4, E14: Blair enlists Nate's help to win over her high-strung boss, Epperly (recurring guest star CAITLIN FITZGERALD – It's Complicated), at W magazine. Meanwhile, Damien (recurring guest star KEVIN ZEGERS) stirs up more drama on the Upper East Side and Chuck finds himself torn between business and pleasure. Plus, musical sensation FLORENCE AND THE MACHINE performs an acoustic version of "Cosmic Love."