Malcolm McGregor was hired as Deputy Sheriff of Lordsburg, New Mexico in 1907. He was 20 years old. That year, his lifelike sketch of a thief on a Wanted poster was instrumental in the arrest of Jake Mackey in Yuma, AZ.

Malcolm is flung into a maelstrom of crime in 1910 when the Sheriff goes on vacation: an intoxicated friend indiscriminately destroying property; bank robbers; illegal racers; and a missing child. And Sabine Cottard, the lead singer of a traveling choral group, who claims to have been knocked down from a fleeing purse snatcher as she left the train. Malcolm nabs the alleged thief at the concert. The boy turns out to be Sabine's half-brother, Paul Guillard, who had been searching for her after his mother died. Sabine rejects him, refusing to believe her father was an adulterer.

After their first sold-out performance at the Lordsburg Community Church, Sabine and the choral group move on to their next venue. Months later, she returns to Lordsburg to show her new husband where the group had its first sold-out performance—and to pay off Paul Guillard. She is now a chanteuse, and married to her agent, Harper Anderson. Malcolm is convinced she sold her soul to a jealous and greedy man and no good will come of it.

On March 15, 1911, Sheriff Kirby resigns his position to take a job in Los Angeles, and Malcolm replaces him. He hires Benjamin Rutherford as his deputy. In late spring he meets Virginia "Ginny" Richardson at a church social for newcomers. They soon fall in love, and marry in May 1912.

In September 1912, he and Ben are ambushed by two crazed escaped convicts, the same men Malcolm arrested in 1910. Although he is wounded, Malcolm shoots them, one dying in the street, the other later that night. Ben was hit in the shoulder, and slowly recovers.

Malcolm turns to his artwork to recuperate from the trauma of killing two men. Ginny encourages him to enter his work in contests and exhibits. Malcolm sends several drawings to Scribner's Weekly and Harper's Monthly. Scribner's buys his drawings and asks for more. Ginny suffers a miscarriage but, when she recovers, they attend a juried art exhibit in Tucson. Malcolm wins second place, and all three of his entries are bought at the charity's auction following the exhibit.

They return home from the art exhibit and find Benjamin Rutherford dead from a stroke. Ben was estranged from his family and Malcolm, grieving for the loss, has him buried in Lordsburg.

A year later, he has accumulated enough money from selling his illustrations and paintings to build a house outside of town. He and Ginny move in and get ready to start a family. Although Malcolm was re-elected as Sheriff in 1913, will he eventually succumb to the increasing interest in his artwork? The Education of Malcolm McGregor reveals the answer and more.