The series premiere introduces the first-responders and 911 dispatchers, including Det. Athena Grant; firefighter Bobby Nash; and dispatcher Abby Clark, who spends her days fielding emergency calls at the 911 call center while desiring to know what happens after she sends help.

A night at an amusement park takes a deadly turn when a rollercoaster malfunction leaves lives hanging in the balance. Abby is relieved after getting some help taking care of her mother and tentatively reaches out to Buck, who is struggling with the life or death nature of the being a firefighter. Meanwhile, Athena and Hen respond to an unusual home invasion and a couple's dispute leads to a dramatic rescue for Bobby.

Bobby and his team respond to an emergency at a children's birthday party that leaves lives hanging in the balance. The crew jumps into action after one of their own is involved in a devastating accident. Athena tries to cope with a tragedy that hits way too close to home and Abby is confronted with a life-changing decision for her mother and makes a connection with Buck

In the aftermath of a deadly plane crash, Bobby and team race to help the survivors, while Athena deals with panic and chaos at the airport. Bobby confronts his past demons; Athena is out for revenge against a group of teen bullies; and Abby delivers an important message from a 911 caller.

The crew races to an emergency at an Indian wedding; Abby enlists Buck to help her find her mother; Abby meets Athena for the first time; Bobby confronts his past; Hen struggles to make the right decision.

On Valentine's Day, a surprise marriage proposal goes awry with dangerous consequences; Athena attempts to help a desperate woman; Bobby and Chimney pull holiday duty; Abby and Buck go on their first official date.