One possible plot is that Carson wakes up on his birthday, but instead of being excited, he feels a great sense of loss due to Jack's death. He starts to go through old photos and mementos of Jack. As the day goes on, some of Jack's family members come to Carson's birthday, as they know Jack would have wanted it. They all sit around and talk about Jack, and Carson realizes that even in death, Jack is still bringing people together. This gives Carson a new sense of purpose on his birthday.
The plot could be that Carson is about to celebrate his birthday. But he is in deep mourning for Jack who has just passed away. Carson decides to have a small, quiet birthday celebration. During the celebration, he shares stories about Jack with his close friends. These stories could be about the adventures they had together or the times Jack helped him. As the night falls, Carson goes to a place that was special to him and Jack and has a moment of silent remembrance.