Airborne is the eighteenth episode of the third season of House and the sixty-fourth episode overall.
Soon another passenger becomes ill with the same symptoms. House assembles a makeshift diagnostic team with three passengers: a boy House instructs to agree with everything he says, a man instructed to disagree with everything he says, and a woman instructed to get morally outraged at everything he says. After a discussion with his "team", House is convinced that both passengers are sick with Ciguatera poisoning because they both ate seafood. He announces to the rest of the passengers who ate seafood should go to the restroom and vomit.
However this theory is contradicted by Cuddy, who is showing similar symptoms despite having not eaten the sea bass. House tells the stewardess to tell the passengers not to worry, but three more people apparently succumb to the same illness. Without any medicine, House goes collect what antibiotics he can from the passengers. Cuddy then persuades House to do a lumbar puncture to find out whether the illness is meningitis. House does the test, which comes back negative. When Cuddy begins to shout at House to cure the sickness quickly, he realizes that she and the rest of the plane are suffering from mass hysteria. He tests this theory by suggesting the passengers that one symptom is uncontrollable trembling of the left hand, which they all immediately start to exhibit.
Peng, however, is still dying, and House believes it is because the man is a drug mule and has cocaine in his system, and prepares to operate. As his "team" holds Peng down, House realizes that the man's pain is eased by pressure. Searching through Peng's wallet, he finds a scuba license and a receipt for scuba gear rental, dated the previous day. Peng is diagnosed with decompression sickness, caused by surfacing too quickly when diving, which was further worsened by boarding an airplane, which is pressurized to 8000 feet above sea level. House tells the flight crew to drop the plane below 5000 feet and get Peng oxygen, and he will be fine.
Meanwhile, at the hospital, a 58 year old woman has been admitted with unexplained seizures and vision loss. With her is an outcall prostitute who had just met Fran, but she stays at the behest of Dr. Wilson, who is leading House's team. Fran admits that she just arrived from a trip to Caracas. Chase and Cameron visit Fran's house to search for clues, but are distracted by the allure of an empty bed. They return without a diagnosis, leaving Foreman with the belief Fran is bleeding into her brain, the solution for which is a hole in her head to relieve the pressure. Chase, however, realizes neither Fran nor her cat have eaten in the last few days, and goes back to the house to find, that when the neighbors had their home fumigated, some of the poison entered Fran's house. Fran is diagnosed with methyl bromide toxicity, and the procedure is stopped before it goes too far.
At the end of the episode, Chase suggests that he and Cameron take their relationship to the next level. Cameron responds that all she was looking for was sex, and says "It was fun. That's it. And now it's over."