The overall director of Los Angeles International Airport (LAX) commits suicide... now his two underlings spar amongst themselves for his former position and title, by attempting to prove they can handle the pressures of operating one of the world's largest and busiest aviation gateways.

When L.A.X. receives word from Homeland Security that a credible threat has put the airport on high alert, Harley and Roger debate over whether to notify the public or continue to keep the news a secret. Tensions build when passengers are faced with longer lines due to extra security, and Roger puts his relationship with his daughter in jeopardy when he refuses to let her fly—forcing her to miss a very important recital. Meanwhile, Tony must take care of a senile old woman who has been left stranded at the airport by her son, who can no longer bear the burden of taking care of her.

A suspended airtraffic controller takes over the control tower.

Thanksgiving Day at LAX bring about some interesting events, both personal and professional, when Henry and Caitlin deal with the fallout when an airline goes out out business and cancels all its flights, leaving hundreds of stranded passengers and a handful of layed off employees in the terminal. Harley and Rodger also deal with a sudden strike by the ground crew, and Harley's estranged younger sister, Julie, shows up and asks her to spend Thanksgiving with their parents, which Harley dispises. Meanwhile, Tony takes charge of overseeing a 10-year-old boy traveling alone to meet his parents, and whom has a big attitue.

As Christmas approaches, events at LAX heat up when the police show up looking for a robber dressed as Santa Claus. Meanwhile, Eddie, seeking a new job as Harley's assistant, meets an attractive barmaid. Roger also deals with being kicked out of his house after he has resumed his gambling addiction and squandered most of his wife's money, while Harley herself flashes back to a previous Christmas during a runway party where she and Roger had a brief fling which almost ended his marriage.

An incoming airliner ""accidentally"" squawks (jargon for transponder code) a Hijack warning. This leads to a full emergency, SWAT, the lot.. Which also leads to a crime of monumental cunning.. Meanwhile, Eddie engages in some crime of his own, Roger's life takes an unexpected complicaturn and Harley moves house.