Wyatt Cole and John "Sack" Halton are paramedics living who love their jobs. Wyatt is given an ultimatum to change his life and must choose between the safe path of medical school and what he loves.
Wyatt has a dream where he has to choose between saving a lady or saving a tiger, and he chooses by doing what he always does - flipping a coin. He is struggling with his feelings for Alice. But then Wyatt sees and old friend who reminds him that sometimes you can't leave the important decisions in life up to chance. Sack tries to reconnect with his son.
It is a night where nothing is what it seems. Wyatt and Sack are called on to a scene in which it seems a man fell out of the sky and onto a woman's car.
There is a heavy fog in Portland. Wyatt tries to teach Sack how to play poker, but Sack loses a big bet and the two are stuck with a difficult patient. The two help a crane operator with chest pains. Wyatt asks his mother, who is a psychologist, to help out Sack's son.
Wyatt's problems with gambling start catching up with him. His brother convinces him to help plan their father's 60th birthday party, which ends up being a very eye opening experience.
Corporate minded Kroll is hired as the new Medic Supervisor which makes life very difficult for Wyatt. Wyatt risks his job to save an accident victim by unauthorized means.
Wyatt and Sack are going through hard times. Wyatt tries to help save Lexi, and Sack is struggling with working two jobs. On top of that, Kroll decides to install black boxes in the ambulances, in order to track them at all times. Meanwhile, Alice helps an old woman dealing with dementia, and Angela is jealous because Harper gets a TV interview.
Alice's mother, who is manic-depressive, comes to surprise her by visiting the ER. She sits down and apologizes to Wyatt about Alice not having their baby... not knowing that Wyatt never knew Alice had been pregnant. Wyatt and John help a wounded gang member.
A man sets off a bomb in a health center, rushing Sack, Wyatt and other paramedics to the scene. Wyatt finds a pregnant woman trapped under a beam and decides to stay with her even when another bomb is detected in the building. He promises her that he will save her baby and decides to keep his promise even after she dies.
Wyatt and Sack celebrate being called heroes after rescuing people at the bombing. But then the father of the baby Wyatt and Sack saved through emergency C-section decides to sue them over the death of his wife. The media jumps on the case and everyone seems to be against them, except Wyatt's father. Meanwhile, sparks fly between Sack and his ex.
Two brothers hold up Wyatt and Sack at gunpoint wanting morphine. Unfortunately, they are out. The brothers then force them plus the patient they were attending to, into the ambulance, get in with them, and make them go to get more. Wyatt's new relationship is affected. Meanwhile, Angela de la Cruz is assigned to temporary duty as dispatcher, driving her fellow paramedics crazy.
Wyatt and and Sack prepare to testify in the lawsuit concern the life of the woman whose baby they saved at the bombing. They realize it could end their career and their friendship. Meanwhile, Angela's girlfriend tries to convince her to take Tango lessons.
Alice is offered a job on the other side of the country, forcing Wyatt to examine his feelings for her. He also tries to help a boy who appears to be the victim of abuse. Wyatt has hopes of rekindling his relationship with Cam's mom, until she tells him she is back together with her husband, who wants to adopt Cam. LifeShield's owner decides to sell the business.