The plane begins to take off while Jake attempts to text his mother to find out what's happening. One of the passengers next to Jake, Marcus, becomes ill.
The stewardess announces the plane is in its final descent to Phoenix. Marcus remains locked in the bathroom while Deirdre and Suzanne plead with him to open the bathroom door.
The captain announces that the plane has been re-routed from Phoenix to LA due to the power outage. Anthony attempts CPR on the collapsed Marcus and as he is further examined it is discovered he has a wound on his abdomen.
Noticing Marcus's wound, Charlie tells the others that they should tie Marcus up. Anthony reveals himself as the Flight Marshall and orders everyone back into their seats. Suddenly, Marcus opens his eyes revealing he has turned.
Marcus has turned into a walker and after a struggle the group shoves him back into the bathroom. Once he is secured they notice blood on themselves and determine that Deirdre was scratched on the arm.
Charlie tells Anthony to secure Deirdre since she has been bit and will turn like Marcus. Charlie tries to convince the Captain to land the plane, but all the cities are experiencing power loss.
Suzanne mourns the loss of her husband from outside the compartment door where he is held while he continues to bang on the door from the other side. Anthony tends to Deirdre's bite wound.
When Suzanne's husband stops banging on the door, she fears that it is a sign he is dying. She then unlocks the cabin bathroom door releasing him into the isle where all chaos breaks loose.
With Marcus on the loose, Jake finds a knitting needle and hands it to Charlie who takes care of the situation. Once it's done, the group notices a crack has formed in one of the plane's windows and it's starting to spread.
Suzanne who has been bitten is comforted by Deirdre while Charlie takes matters into her own hands concerning how to deal with the bite wound. The window which has been slowly cracking finally completely shatters.
As the airplane cabin depressurizes, the passengers struggle to find available seats and strap on oxygen masks. Charlie and Jake buckle in next to each other and she makes a startling revelation to him.