SPOILERS for the Season 3 finale of Manifest are ahead.
The NBC drama centers around the 191 ticket holders whose aircraft experienced turbulence in the air in 2013. When the plane ultimately lands in New York, they learn that five-and-a-half years actually passed, though they themselves haven't aged.
The passengers bond with one another as they try to reintegrate back into "normal life." They're all also dealing with the fact that their loved ones, who assumed they were dead, have moved on.
Ben Stone (Josh Dallas) and his young son, Cal Stone (Jack Messina) were on the plane, while Cal's mom, Grace Stone (Athena Karkanis) and his two sisters stayed behind.
At the end of Season 3, in the two-part "Mayday" finale Cal mysteriously disappears. What happens to him?
Does Cal Stone die in 'Manifest?'
In "Mayday," Cal gets a "calling" to go to the Project Eureka facility to touch the tailfin of the 828 plane. While there, Cal reunites with his parents, who implore him to go home.
He says that he can't go home, and he then shows Ben and Grace a set of burn marks on his stomach. When he's getting the burns looked at, Cal tells his parents that everyone at Project Eureka should stop testing the tailfin.
Later on in the episode, Ben is trying to destroy the remaining piece of the plane in order to save Cal's life. When this proves to be unsuccessful, Ben realizes that he needs to return it to the ocean, where it originally came from.
Before he can do that, Cal touches the tailfin and he disappears. The stakes are now higher than ever before for Ben to get the tailfin back to the water.
He manages to convince Dr. Gupta (Mahira Kakkar) that it's the right thing to do, and he teams up with Saanvi (Parveen Kaur) to make it happen.
The two place the tailfin in its original resting place during a severe storm, and Saanvi almost dies.
Ben and Saanvi find themselves in a calling on Flight 828, where they reunite with Cal. However, Cal ominously says that "it's not over," and Ben begs to find out where he really is outside of the calling.
Meanwhile, Ben's sister, Michaela Stone (Melissa Roxburgh) has also joined the calling on the plane. She begins to put the pieces together with regards to what Cal is talking about.
She determines that Angelina Meyer (Holly Taylor) is the one who everyone needs to be worried about. She has identified Cal's baby sister, Eden, as her guardian angel. She goes to take the baby from the Stone family's home, but Grace tries to stop her.
Angelina ends up stabbing Grace in the stomach and she leaves with Eden. As Grace is laying on her bedroom floor, a teenage version of Cal (now Ty Doran) emerges. He's the age he would have been had he not been on the plane for more than five years.
The older Cal stays with his mom in her final moments. Cal does not die at the end of Season 3, but it's not yet clear why he's suddenly a teenager.
Does Grace Stone die in 'Manifest?'
Though many viewers had suspected that Cal would be the one to die at the conclusion of Season 3, Grace ends up perishing from the stab wound.
In her final moments, Grace asks that her son makes sure that the rest of the family members "take care of each other."
Cal promises that he will, and he tells his mom that it's OK for her to let go.
In the last seconds of the episode, Dr. Gupta sees the entire 828 plane put together at the Eureka headquarters. She briefly notices the pilot as well before he disappears, along with the structure.
You can catch up on Season 3 of Manifest on NBC.com and Hulu. The first two seasons can also be streamed on Netflix.