On the last episode of "Chicago Fire," a seemingly slow night at the firehouse turned into a night of frenetic chaos. 

The night begins quietly, with Katie (Brittany Curran) telling her big brother Severide (Taylor Kinney) that she is moving to New York to open a restaurant with her boss. While she feels guilty about moving due to her new relationship with Otis (Yuriy Sardarov), she doesn't tell him the news just yet. 

The firehouse then gets a call to a car wreck with a teetering power line. When they get to the scene, they discover an injured body and a passed-out drunk driver. The power line then hits the ground, and plunges the entire area into complete darkness. 

Boden (Eamonn Walker) offers those without power to come to Firehouse 51, where they have a generator. That is, until the furnace breaks.

Severide and Casey (Jesse Spencer) are trying to fix it when Severide realizes that Casey is still suffering from memory loss, as he is forgetting the names of common tools. They argue about his ailment while a fight breaks out between two civilians in the kitchen. The instigator, who goes by the name Keeler, grabs a knife and points it at Severide. Severide quickly disarms him and throws him out into the cold. 

Detective Lindsay from CPD (Sophia Bush) tells Boden, Casey and Severide that Keeler has a violent past, and is talking about killing a fireman tonight. She tells them to stay away from him. 

While Clarke (Jeff Hephner) is getting more food at a corner store, looters enter the stockroom and stab the owner. Clarke scares them off with a bat, but the thieves return, ready to fight. CPD officers then come by in the nick of time and break it up.  

Meanwhile, an older woman has a heart attack at the station, which leads to a collision between Shay (Lauren German), Dawson (Monica Raymund) and Rafferty (Christine Evangelista). But once Rafferty and Shay revive the woman, Dawon gives them credit where credit is due. 

Det. Lindsay tells the firefighters that Keeler has an inside man who wants to murder Severide. Casey catches the man, but the man punches him hard. Casey believes he's fine until he sees blood dripping out of his ear. 

As dawn breaks, the power comes back.

As Katie is walking back to her apartment by herself, two men put a sack over her head and throw her into a van. 

Although the show is going on hiatus due to the Sochi Winter Olympics, four Dawson-centric webisodes will premiere online on NBC.com during the break. 

The webisodes, which debut Feb. 11, include Dawson taking on a crisis near the station when she is the only one around to respond. The storyline will chronologically follow the drama's recent episodes. The first and last installments will include Cruz (Joe Minoso), Mouch (Christian Stolte), and Hermann (David Eigenberg). 

Regular episodes of "Chicago Fire" return on Tuesday, Feb. 25 at 10 p.m. on NBC.