Andy and Sam arrest a bank robber while he's shopping at a small grocery store shortly after the robbery. The blue dye on his face alerted the clerk to call the police. Traci and Gail arrest a man they think is intoxicated. Gail's big complaint is that the man vomited on her hair. He begins to have a seizure after they get him back to Division 15 and he's taken to the hospital. Traci rides along in the ambulance and is stuck with a bickering married paramedic team, Charlotte and Martin. Once they arrive at the hospital, doctors say that they can't identify the man's condition and everyone needs to be quarantined, meaning Traci is stuck with the bickering couple. Everyone at Division 15 is also on lockdown due to the quarantine.
Andy recruits Chris for some help on getting information about her bank robber. Chris poses once again as a male prostitute and is thrown into the same cell as the blue robber. After being extremely annoying, he was able to get some information out of the man. Dov is on a date with Sue, the bomb squad member who saved his life a few weeks ago. Luke runs into him there and tells them that Andy has called for their help in the investigation since everyone at 15 is on lockdown. They head to the hospital to interview the manager on duty who was assaulted during the robbery. He's able to identify the arrested blue man as James Mitchell, an angry customer who had recently gotten desperate after his home was foreclosed. Right before he was caught, he swallowed something which turned out to be his wedding ring. He did it to protect his wife and also his partner in the crime. Ben and Dov along with a SWAT team head to the foreclosed home and arrest his wife. They're not bad people, just desperate and Jerry lets the husband and wife reunite in the cell.
Traci learns at the hospital that the intoxicated man has died which means that an autopsy should yield some clues to his illness. Everyone is getting a little nervous, especially Gail. Since she had the closest contact with the victim, she's being isolated in Frank's office. Frank and Noelle have been going to dinner every Friday night. Noelle begins to wonder what this will mean since she still wants to have a baby and tells Frank about her plans to have a baby. Frank doesn't have an answer. Traci finally has had enough and yells at Charlotte and Martin to stop bickering. When she tells them she's scared and she has a child, they suggest she record a message to her son, Leo which they help record. Soon after, they learn that the suspect was not contagious but died of Naegleria fowleri, an amoeba found in the water he examined for a living. The news spreads to 15 and people are happy to be able to finally go home.
Dov and Sue kiss on the park bench at the end of an eventful first date and Sam helps Andy take out her aggression by having her put on gloves and box with him which helps her feel much better.