Detective Lovato's past as an undercover officer tangles up with her present duty when one of the gang members she ingratiated herself in and developed feelings for turns up tortured and killed.
Navid sets Dixon up with some studio time to make up for rescheduling his appointment with a music producer, but Dixon feels pressured to create a hit song before he runs out of studio time. Naomi makes plans to get revenge on her rival, Holly, and her sorority during the Greek games. Much to Naomi's dismay, she needs Austin's help to carry out her plan. Silver directs a commercial for Liam's bar, while Ivy feels torn between her relationship with Raj and her friends.moreless
A comet is due to pass by Earth, but its trajectory changes to a collision course, causing widespread panic. When the comet appears to slow down — as if it's coming in for a landing — 4,400 people are deposited in an explosion over Highland Beach.
The returnees — "the 4400" — have been missing from months to years. None have any memory of where they've been, none have aged, and a small number are beginning to manifest paranormal abilities. Tom Baldwin and Diana Skouris, two Homeland Security agents, are appointed to find out what happened to the 4400.