Brother and sister find themselves at the center of devastation in “Manifest,” and watch Jim Carrey do what he does best in “The Mask.”

What’s on TV

9-1-1 9 p.m. on Fox. The season finale of this series finds the emergency workers under more stress than usual during the holidays. A stampede at a toy store, a less-than-successful mistletoe stunt and a Christmas-light showdown, which ignites a neighborhood’s competitive edge, create an atmosphere conducive to chaos. On top of it all, Eddie (Ryan Guzman) grapples with whether he’s going to let his son visit his mother, knowing it’s the only thing he truly wants.

MANIFEST 10 p.m. on NBC. Michaela (Melissa Roxburgh) and Ben’s (Josh Dallas) plan to save the other missing passengers goes wrong and lives end up being lost in this season finale. In the wake of the devastation, Ben and Grace (Athena Karkanis) reach a breaking point, while at the other end of the spectrum Michaela and Jared (J.R. Ramirez) are getting far too close.