The 15th and final season of ER begins with the devastating repercussions of the ambulance explosion. As Morris and Neela do everything they can to save a wounded colleague, Abby treats a young girl injured during the blast.
Charlie finds out that the waitress has been seeing someone. He calls on Mac, his so-called best friend, to find out more information about the guy and to beat him up. However, it turns out that Mac is the guy the waitress has supposedly been seeing. Dennis, heartbroken that he's not Charlie's best friend, tries to win him over.
Due to the gang's latest "business expenses," Paddy's is in dire need of money. Frank buys a billboard to advertise the bar, but Dee decides to create a viral video to post on YouTube for promotion. Charlie quickly joins her, leaving Frank and Mac to hold a contest for some hot models to feature on the billboard. Naturally, Dennis joins the competition to prove his worth.
Dawn has entered the latest contest held in Celestic Town. Dawn meets her mother's old rival Yuri, that wants to win this contest. When she and her mom's rival "Lila" (Yuri in Japanese version) come face to face in the Finals of the contest Dawn has to give it all she has to win. Dawn wins the Celestic Town ribbon and her third contest ribbon.
Brock is away on an errand. When they can't handle it, they send Gliscor to bring Brock back. Brock finds he can't carry Gliscor back, as it can't glide in the wind going the opposite direction, and leaves it, promising to return for it. At the end of the episode, the gang comically realizes that they left Gliscor behind, and scene shows a frustrated Gliscor with a long way to go.
When Mrs. Beady tries to run for mayor, Otis decides to run for mayor against her to avoid Mrs. Beady from exposing them as talking animals. Their competition goes horribly out of control, however.
Mike and KITT must deliver a package -- a task that seems easy enough until they learn the package is a man with a code built into his DNA. The task becomes more difficult when a mysterious woman gets in their way.
Christine offers to marry Barb to help her stave off deportation. Meanwhile, Richard looks to pop the question to New Christine.
The club travels to Nevada to store arms with a brother club; when the Mayans pose a threat, Clay decides to "patch-over" the tribe, making them an official charter; Tara's ex, an ATF agent, investigates SAMCRO.
This episode demonstrates the production processes for pencils, metal recycling, coffee.
When Kenny becomes Joy's new "girlfriend," Eddie feels left out and gets jealous of their girl-talk. In an attempt to feel included, Eddie crashes Joy's '70s-themed work party and sends Joy to the hospital in a disco mishap.
Josh is on the island of Java in search of a bat with a 12-foot wingspan (that's not a vigilante). Then the team heads to the Philippines to hunt down a huge, mysterious river creature.
Bitsy Mae speaks to the church; Peggy explains her reasons for taking Bitsy Mae in; Brother Boy is troubled in Dr. Eve's therapy; Sissy, Noleta and LaVonda search for a missing Latrelle.
When an SUV carrying members of the team explodes, the rest of the team fights to save them and catch the terrorists responsible for the bombing.
The contestants are given the task of designing for each other, inspired by different genres of music. They have $150 and one day to complete the challenge.
Picking up where the season 4 finale left off. The team is investigating the death of a woman named Lauren Santana whom is linked to the bank robbery. She is a friend of Flack's sister Samantha. Also Mac has escaped the robber but the bodies are still piling up. So the team must quickly find the bank robber before he is able to get away.
The pieces of a dismembered body are found lying in a purple pool of water, except the head is missing. The team finds that the body belongs to Jared Addison, a science fiction writer who had several mental problems. With Sweets' help, several suspects are hunted down, however the team has trouble finding enough evidence with the victim's head still missing.
Trust issues are produced by a scientific find, along with sinister results. Zoe's life is in jeopardy, and Eva Thorne knows what has caused the predicament.