The entire unit has to deal with a dangerous substance, and not everything goes smoothly. Roope vents his frustration on the new fire master Krista. Mikael has a hard time facing his aging. Pietu won't leave Nella alone.

Jasper plays hero in the fire and hears about it. Roope's face is tense and he vents his bad feelings on the wrong targets. Nella notices new pleasant aspects of her work partner.

Nella and Pasi are forced into a high crane for rescue missions. The shared experience of a challenging task brings them even closer. Krista will receive an honor on the rescue service's anniversary. Roope has challenges adapting to new family arrangements.

Mikael's age crisis is not going to ease him and he comes up with new ways with Niko's help. Nella promises to help her ex Pietu, even if she wants to focus on someone else.

Roope and Elisa's visit to the babysitter causes Roope's ability to concentrate to disappear. Nella and Niko get into danger at the fire gig because of Roope's misjudgment. Mikael is like a changed man who makes Ansku's doubts rise to the surface.

A violent bomb attack in the center of Kotka arouses strong emotions in everyone. Krista hears the reasons for Roope's absence and decides to reconcile with Roope. Nella gets help from Pas when the worst comes true.

Roope returns to work tense about how others react to him. Nella is still in shock from everything that happened, but is trying to move on. At night, the alarm gig comes to a familiar address. Not everyone survives a fire with their skin intact.