Mandy Moore
Cast member Milo Ventimiglia (R) and Mandy Moore (L).Reuters

Tuesday's episode of This is Us, which has been receiving rave reviews ever since it aired, will probably explain what happened to Jack, as the previous season saw Randall's children addressing another man as their grandfather.

In the episode, Rebecca was still wearing the chain that Jack gifted her, and this has sparked speculation that Jack might have passed away. But there is also a possibility that Jack and Rebecca separated.

"I'm rooting for Jack and Rebecca," Mandy Moore told Entertainment Weekly. "I want to know their story, I want to know where that disconnect is, because I just love them so much from the first episode. I'm anxious to see where they go, what this journey is… And I'm excited, too, that we're not married to having that storyline in any sort of real time, because we're jumping around."

Episode 3 is titled Kyle and it will see Kevin deciding to take control of his future and move to New York City to pursue a career on Broadway. He naturally expects his sister Kate to follow him, but Toby, Kate's new boyfriend, might prove to be a problem.

Will Kate tag along with her twin or will she stay back to see where her relationship with Toby goes? According to a TVGuide report, the choice Kate makes might be the best one for her.

The synopsis for Kyle reads:

Rebecca encounters Randall's biological father when she makes a surprise visit to her son's home; Kevin decides to move to NYC to pursue a job on Broadway; and Toby plans a special day for Kate. In the past, Rebecca and Jack take their new babies home from the hospital and struggle to cope with the loss of a child.

This is Us airs Tuesdays on NBC.