It's Greg Pratt's last shift at County General and he treats a number of cases that were started by John Carter on the day shift. They treat a 12 year-old near drowning victim who has little chance of recovery; a Buddhist nun who has a special gift of seeing another's inner self; a woman who is convinced that the day's solar eclipse signals the end of the world; a drug addict who scams both of them for pain medication; and a pregnant woman who had her baby torn out of her womb. Dr. Romano has his re-attached arm amputated. Carter receives a call from Luka Kovac asking if he can come to the Congo and help out. Abby is none too pleased. Meanwhile, Doc Magoo's burns to the ground.

John Carter arrives in the Congo to find that Luka Kovac is away at a distant clinic administering vaccinations to the local population. He also finds appalling medical conditions. Too few nurses and doctors, limited equipment and few medical supplies are par for the course. That aside, he gets s great deal of satisfaction from the work he does. He meets Gillian, a Canadian nurse, and learns that she and Luka have become close. He tries desperately to save the life of a severely wounded man which pays later dividends when their camp is invaded by rebel troops and their lives are threatened.

John Carter returns to the Congo to retrieve Luka Kovac's body. He finds however that the area where was killed is still too dangerous to enter. He and Gillian finally manage to hitch a ride with a Red Cross worker, Debbie, who is going to the area. In flashbacks, we learn how Kovac and his fellow aid workers were taken prisoner by rebel troops. They are shot, one at a time, until only Luka is left. Amid the destruction of the eastern Congo, we learn his fate. Carter also makes a fateful decision.

Luka Kovac arrives safely at County General and is hospitalized for treatment. His friend Gillian delivers John Carter's letter to Abby. Pretty much everyone gets to read it when Frank retrieves it from the garbage and passes it around. Greg Pratt has dinner with Chen and her parents. The dinner goes well but they have a serious argument afterward. Dr. Romano is unhappy with his prosthetic arm which makes him even more difficult to deal with. Some of the more senior nurses find their hours being reduced as a cost-saving measure and stage a walkout. Romano's response is to fire them all. Dr. Lewis treats a teenager with a serious heart problem but her parents insist that she not be told immediately. A new group of second year residents arrive.

Confident second-year resident Pratt wants to prove his abilities when he works the graveyard shift (11 p.m. to 7 a.m.), but his heroics sometimes backfire. Pratt shows contempt for a man, Ed Gamble, who presents no symptoms of disease but temporarily loses his speech. Chen continues to get in the way of Neela's progress as her jealousy regarding Chief Playa Pratt's flirtations with everyone who wears a skirt reaches new levels of ridiculousness.

Dr Morris agitates a patient who then leaves, steals a tank, and rampages through Chicago on his way to County General. He makes it all the way to the ambulance bay before the CPD finally stops him. Sam tries to figure out her relationship with Kovac while Gillian shows up at the ER to cement plans for dinner with Carter, Kem and Kovac - making things that much more difficult. Neela confronts Frank about his arrogant bigotry, bluntly telling him she wants nothing from him but silence from this point forward. During the initial onrush of patients due to the tank rampage, Frank has a heart attack which is, thankfully, caught. Frank's wife and daughter show up and are rushed up to the cath lab where Dr. Pratt is helping Dr. Kayson keep Frank alive. In the end, Neela winds up in the family room with Frank's family listening to them describe a side of Frank that no one has ever seen. Meanwhile Kovac treats a 13 year old with chlamydia and counsels him to contact his sexual partner - which turns out to be quite a few teenage girls.