‘This Is Us' Cast Teases Groundbreaking Baby Jack Episode and Series Finale (Exclusive)

The stars of 'This Is Us' are getting ready to say goodbye! ET's Denny Directo caught up with the cast at the show’s opening night celebration at PaleyFest. Chrissy Metz and Chris Sullivan, who play Kate and Toby, preview the episode told from the perspective of their on-screen son, baby Jack. Then, Mandy Moore, Susan Kelechi Watson, Milo Ventimiglia, Sterling K. Brown and Justin Hartley all reveal what they're most excited for fans to uncover in the series finale. 'This Is Us' airs Tuesdays on NBC.