'This is Us' season 1 episode 9 spoilers, news: Randall learns heartbreaking secret; Pearson family gathers to celebrate Thanksgiving

The Pearson family celebrates Thanksgiving in the upcoming episode of NBC's hit drama "This is Us" season 1.

Titled "Pilgrim Rick," next week's episode will see the family celebrate a traditional holiday. According to the official synopsis, Jack (Milo Ventimiglia), Rebecca (Mandy Moore) and the three kids will head to the house of Rebecca's parents to celebrate their traditional Thanksgiving holiday. However, while on their way, an unforeseen detour occurs. In the present, Kate (Chrissy Metz) makes two serious life-changing decisions, while Kevin (Justin Hartley) brings Olivia (Janet Montgomery) to Randall's (Sterling K. Brown) house for Thanksgiving. Despite the joyous occasion, Randall's heart gets broken when he discovers a lifelong secret his mother has kept from him.

Speaking with Entertainment Tonight, Brown revealed why Thanksgiving is dubbed as Randall's holiday. "He lives for Thanksgiving, year in and year out," Brown hinted. "And it's because of something in their past as a family that made Thanksgiving this incredibly special moment." As most family reunions go, the chances of the Pearson's get-together going off without a hitch are slim."Some things come bubbling up to the surface and not everything goes as planned," he continued.

The past few episodes have already established that Jack is already dead in the present day. However, the how and when he died remain mysteries for viewers to solve. In the same interview, Moore assured fans that they will eventually have answers, but it won't be as quickly as fans would expect.

"I wouldn't wait with bated breath, episode by episode, like what giant revelation is going to be revealed in this episode," she explained. "I think some episodes, there will be bigger pieces of information that sort of unfold and then smaller things that still resonate and are somewhat satisfying."

Keep tuning in to "This is Us" season 1 every Tuesday night at 9 p.m. ET on NBC.