'This Is Us' season 1 winter premiere spoilers, cast news: Randall deals with his father's new relationship; Hari Dhillon lands recurring role

Toby's (Chris Sullivan) heart attack puts Kate (Chrissy Metz) in a tough spot on the upcoming episode of NBC's hit drama "This Is Us" season 1.

Titled "The Right Thing to Do," the show's winter premiere will explore the aftermath of Toby's shocking heart attack when he visited Kate. According to the official synopsis, Kate struggles with her feelings after finding out about Toby's heart attack. While William (Ron Cephas Jones) starts to spend more time than usual with Jessie (guest star Denis O'Hare), Randall (Sterling K. Brown) must get used to the idea that his father now has a new relationship.

Back in the past, Jack (Milo Ventimiglia) and Rebecca (Mandy Moore) are determined to find a way to afford a house that can accommodate three children. Olivia (Janet Montgomery) suddenly resurfaces, surprising both Sloane (Milana Vayntrub) and Kevin (Justin Hartley) when they cross paths with her.

Speaking with E! News, Moore revealed that Jack and Rebecca's efforts to find a new home will give viewers a look at a slightly different time period of their lives. "We're going back in time and it's when we find out that we're having triplets, and we're not just having one baby, so chaos ensues from there, obviously," she teased. "Our whole world is sort of flipped on its head," Moore added.

Aside from issues at home, Randall is also bound to deal with complications at work. "Law & Order: SVU" actor Hari Dhillon has joined the series to play a recurring character who will have ties to the Pearson son. Reports say that Dhillon will portray the role of Sanjay, a new workplace rival for Randall. Details on how they'll become rivals are unclear, but Sanjay's arrival will certainly reveal a new layer to Randall's personality.

The first season of "This Is Us" returns to the small screen on Tuesday, Jan. 10, at 9 p.m. ET on NBC.