The series revolves around Rebecca Pearson, who is having trouble in her pregnancy with triplets. Then she gives birth on the day of her husband's 36th birthday, and events begin to reveal the story of Rebecca and her husband Jack.
The Big Three continue searching for self-fulfillment while trying to honor the legacy of their late father, Jack, as the circumstances surrounding Jack's tragic death come to light.
In season three, the Big Three find themselves on a new path as they celebrate their 38th birthday. Jack and Rebecca go on their first date, the Pearson family supports Kevin in his first film, and the three teens make college decisions.
As Beth and Randal try to adapt to their new life in Philadelphia, Kate and Toby adjust to baby Jack's diagnosis, as Kevin builds a relationship with Nicky.
During the Coronavirus pandemic, Madison, Kevin, Kate, and Toby go on a trip to Rebecca's cabin to escape mingling and the risk of getting sick. Eventually, everyone's suffering quickly materializes during a difficult period in their lives.