A series of ransomware threats leads to an overabundance of emergencies for the 118, including a medevac helicopter crash at a hospital and an air-traffic control tower system failure. Meanwhile Athena must revisit her traumatic attack when the case of the realtor serial rapist goes to trial, Eddie suffers a health scare and Maddie's postpartum depression worsens.

The 118 springs into action when a city-wide blackout and a record heatwave causes mayhem in Los Angeles. Meanwhile, Chimney confides in Hen about Maddie's condition, and Athena's worst nightmare comes true.

After a mysterious death, Hen and Chimney put their lives in danger when they suspect that someone is playing God to make themselves look like a hero. Meanwhile, Eddie visits Texas, where he attempts to reconcile with his father.

Despite the case being closed, Bobby is determined to prove his AA sponsor was murdered and bring his killer to justice; Meanwhile Buck struggles with his post-traumatic stress.

Following the devastating fire at the Nash home, Bobby's fate remains uncertain, while Athena embarks on a mission to uncover the truth. Meanwhile, Hen and Karen engage in a heated custody battle, while Christopher grapples with forgiving Eddie.