The season finale’s shockers don’t end there. Earlier in the episode, Cal visits the tailfin, hoping to find the source of his callings. Against Ben and Grace’s wishes, he goes to Eureka to touch the tailfin but then disappears. Ben and Saanvi then try to save Cal by returning the tailfin to the ocean, where Ben found it in the season premiere. Unfortunately, they’re too late.
After Ben finally reunites with Cal on Flight 828 through a calling, Cal says goodbye to his dad, saying, “This is how it has to be.”
At the end of the episode, viewers learn what Cal meant when he returns to the Stones’ home to bid Grace farewell. In a shocking twist, Cal reappears as a teenager, the same age he would’ve been if he had survived the crash.
Source: https://www.distractify.com/p/manifest-season-3-recap
