Houdini & Doyle (2016)

S9E1 The Locket

Title: The Locket Plot: As Robin and Barney head to Long Island for their wedding festivities, they stumble upon a surprising revelation about their family history. Simultaneously, Marshall encounters a surprising online find that alters his plans for the trip. Meanwhile, Lily takes the opportunity to challenge Ted on his reluctance to move on from Robin, leading to an emotional confrontation.