Exposition (Initial Situation)
Club Med School
A plucky young man named Martin Arrowsmith enters medical school with stars in his eyes. He wants to become one of the greatest scientists the world has ever known, and he believes he can accomplish this by working with one of his professors, Max Gottlieb. He finds out after reaching the school, though, that everyone considers Gottlieb an old crankypants. Most of his fellow students are way more interested in earning a big fat salary than pursuing the truth.
Before finishing, Martin also gets himself into a pickle by getting engaged to two women at once. He ends up marrying the more laid-back of the two, whose name is Leora.
Rising Action (Conflict, Complication)
Fail Again, Fail Better
After finishing med school, Martin moves with Leora to her hometown. Martin isn't exactly a people person, though, and he never manages to build a solid medical practice because people don't like him. Martin and Leora move on to another city, but the same thing happens all over again. Martin is a gifted scientist, but he doesn't realize that most of the time, people don't want to hear the truth. For a second time, he gets run out of town.
After some deep soul searching, Martin receives a letter from his old mentor, Max Gottlieb, inviting him to take a job at the McGurk Institute in New York, where Martin will be able to pursue his scientific interests solely for their own sake. But once he gets there, Martin realizes that he's still going to be pressured to turn his research into something practical that will make people's lives easier.
Climax (Crisis, Turning Point)
While working at McGurk, Martin accidentally discovers a type of organism called a phage that can destroy the bacteria that causes many diseases (including pneumonia). Instead of rushing to publish his findings, though, Martin decides to do his due diligence and spend more than a year testing his findings. By the time he gets around to writing his paper, another doctor in France has already made the same discovery.
Martin's dedication to his scientific values has cost the McGurk Institute a lot of money and international acclaim. The best way for him to make up for it all is to travel to a Caribbean island that's riddled with plague and to use one of his Institute's vaccines to squash the disease.
Death and Craziness
While visiting the plague-riddled island of St. Hubert, Martin realizes that the only way to test the scientific value of his vaccine is to inject only half of the infected people and to let the other half die. He knows that this will causes thousands of deaths right away; but it could also prevent millions of deaths in the future. While he's putting this plan into action, his wife Leora dies of the plague. After finding her dead body, Martin goes crazy and dishes his vaccine out to whoever wants it, thus ruining his experiment… but saving lots of lives.
Martin buries his wife, returns home, and marries a rich young lady shortly after. It doesn't take long for him to decide that he's not cut out for high-class living. He leaves his wife (and their new son) to go live in the woods of Vermont and work on science experiments for the rest of his life.
Nobody Said It Was Easy
Like a true scientist, Martin plunges into his experiments and never thinks about the outside world. In a last ditch effort to save him, his wife shows up with their son and pleads with him to come home. He refuses, though, and tells her to send their son his way when the boy gets a little older. And that's it. Martin totally chooses science over domestic life, and he never looks back.