Since its premiere, "This Is Us" has been a huge hit. This heartwarming show is undeniably NBC's breakout hit show of fall 2016, winning audiences over with its stellar cast and mind-blowing twists.

Titled "Almost Christmas," the fall finale aired on December 6 and was, as expected, packed with shocking twists.

The heartwarming episode followed the Pearson family and the other characters as they celebrated Christmas Eve. The members of the family tried to make it a happy occasion despite Randall's reluctance to reconcile with Rebecca.

"The Pearson family finds themselves at the hospital on Christmas Eve after little Kate comes down with appendicitis. When they run into Dr. K, who is alone at the hospital, they realize they need to be there for him as much as he was once there for them. Presently, Kevin celebrates Hanukkah with Sloane and her family, Kate continues to pursue her big surgery and someone from William's past reappears in his life," reads the description for the episode.

When the series premiered, viewers learned that Jack and Rebecca Pearson were Kevin, Kate and Randall's parents. However, it was not until recently that it was revealed that Jack was actually dead in the present, Rebecca was married to his best friend and Rebecca knew who Randall's real father is since the very beginning.

The previous episode titled "The Trip" revealed that Rebecca also knew that William, Randall's father, was battling his addiction to drugs and was making a living through music. However, she decided to never tell Randall the truth.