CHIN's

Bobby Nash decides to move to Los Angeles in the hopes of restarting his life after a devastating tragedy that struck his family back in Minnesota, but in Los Angeles, he first meets Athena Grant and works his way to captain of the 118.

A going-away party for a bank manager turns into an emergency, and then a mystery, as the first responders are accused of pulling off a daring heist.

When Metro LA's 9-1-1 system is hit with a massive system-wide power outage, the call center must go old school in responding to emergencies. The first responders must deal with explosions in multiple homes and a difficult child birth. Meanwhile, Michael confronts Bobby about parenting his kids.

The First Responders rally together to search for a missing Maddie.

Look back at how Chimney joined Station 118 and became the firefighter and paramedic he is today.

Bobby meets Athena's parents for the first time and Maddie attempts to end her marriage for good, causing Doug to insinuate himself even deeper into Chimney's life. Meanwhile, a tanker carrying a tiger shark crashes on the freeway and a gas leak in a plastic surgeon's office happens mid-surgery.

The holidays are naughty and nice for the first responders, who must deal with a stampede at a toy store, a mistletoe stunt gone awry and neighbors competing in a Christmas-light showdown. Meanwhile, Bobby contemplates his future with Athena, Chimney and Buck attempt to lift Maddie's spirits and Eddie must decide if he wants to give his son what he really wants for Christmas – a visit with his mom.

Hen relives her evolution into the firefighter she is today as she recalls the first times she met Chimney and Athena.

Buck jumps back into the dating scene but fears he will return to his old ways; a woman goes to great extremes on a freeway overpass to get the attention of her husband; a couple have a car accident on their wedding day.

Halloween finds the first responders racing to the rescue at a cemetery, a haunted hayride and a spooky Hollywood parade; Meanwhile Maddie thinks she has received a "ghost" call from a missing hiker; Hen finds herself facing with a life or death situation with the father who abandoned her; Eddie reconnects with his estranged wife.