Gossip Girl’s fashionable Upper East Siders returned to the CW last night for another episode counting down to the series finale. And aside from the drama, the fashion kept us watching yet again. Serena van der Woodsen (Blake Lively) kept it colorful in a cobalt Marc by Marc Jacobs dress, while Blair Waldorf (Leighton Meester) brought back a sophisticated version of her once-signature headband to accessorize her Alice + Olivia skirt. For more looks from the new episode, titled “High Infidelity,” click through the gallery. Catch Gossip Girl every Monday at 9/8c, and check back on news.instyle.com to get all the weekly fashion credits.