Get ready for the biggest shocker yet on The Event: There isn't only one event! "Major large-scale, potentially world-changing events will end every season," says executive producer Evan Katz. The first of which, he hints, is a humdinger that will alter the entire world. But before that, NBC's spooky sci-fi saga will leave viewers guessing with a November 29 mid-season finale full of twists and danger. "We'll learn a great deal about Sophia's people: how many there are, how they've integrated and what the status of Sophia's leadership over them is," says Katz. Complicating matters for the survivors is a new alien villainess (Necar Zadegan) "who presents a challenge to Sophia's leadership."

Meanwhile, President Martinez (Blair Underwood) will face a military crisis, and Sean (Jason Ritter) and Leila (Sarah Roemer) get closer in their search for her abducted little sister, Samantha. While on the hunt, Leila will uncover a stunning revelation about one of the characters that will change everything. Again.