One unfortunate side effect of writing the definitive account of the Columbine massacre: Author Dave Cullen has become, by his own account, “a talking head … the mass murder guy.”

This likely sets up unreasonable or confused expectations for Mr. Cullen’s new nonfiction tome, “Parkland.” While “Columbine” was a decade-in-the-making exploration of the 1999 Colorado school shooting from every conceivable angle, “Parkland” is something entirely different. With a release date that coincides with the one-year anniversary of the mass murders at Marjory Stoneman Douglas High School in Parkland, Fla., this book deals very little with the killings and very much with their aftermath. Specifically, Mr. Cullen examines the March for Our Lives movement started by a select group of MSD students. After years of dwelling in the darkness of reporting on school shootings, Mr. Cullen embraces an opportunity to share what he clearly views as a ray of hopeful light.

The idea for a longer work springs from Mr. Cullen’s reporting on the Florida tragedy for Vanity Fair. “Once I met those kids,” he writes in the “Notes on Sources” section of the book, “I was hooked. … I could not bear the idea of not telling their stories.”

This plays into a strength of Mr. Cullen’s writing — he clearly and engagingly tells multiple stories simultaneously and brings a great number of people to vivid, distinctive life. He manages to flesh out and bring something new to the stories of the kids most readers likely know best, Emma Gonzalez and David Hogg. Even more interesting is getting to better know what makes others in the movement — like super organizer Jackie Corin and the initially wide-eyed freshman Daniel Duff, who had seven friends die in the attack — just as compelling.

Mr. Cullen also makes a point of telling the stories of important players the MFOL kids initially overlooked, including teens D’Angelo McDade and Alex King of the Chicago-based Peace Warriors and African-American classmates like Tyah-Amoy Roberts. He even includes MSD kids who did not want to be part of anything political after what happened and feel their voices have been neglected in the rush to turn what happened at their school into no more than a crusade to stop further school shootings.

The chapter “The Memes Men” should be required reading for anyone convinced that teens are incapable of large-scale, committed action, for any teacher still leading class as though kids don’t realize they are a mere click away from nearly anything they want to learn or create. Mr. Cullen spends time at the MSD students’ office and marvels at their savviness in quickly creating purposeful and engaging content for their peers. What irony that, in a world ruled by sound bites, Mr. Cullen treats readers to an in-depth exploration of young people discussing how to offer more effective sound bites in service of their movement.

The book never turns into a diatribe about how best to curb gun violence and prevent more school shootings but clearly favors what is depicted as a reasonable set of five demands developed by March for Our Lives. Mr. Cullen sees the student organizers as true change agents of the American political landscape, even as he avoids digging too deep into why and how their calls for background checks, a searchable Bureau of Alcohol, Tobacco, Firearms and Explosives database, Centers for Disease Control and Prevention gun violence research funding, and a ban on semiautomatic assault rifles and high-capacity magazines might be a most effective way to curb or end mass murders. Such considerations are dealt with in context as the MFOL kids strive for continued relevance with the mainstream media and with the dilemma of how to get people to demand more than the entrenched views, and typical inaction, of representatives of the two major American political parties.

Part character study, part media analysis, part political critique, “Parkland” ends up being many things. Thanks to Mr. Cullen’s gift for clear, involving storytelling, it ends up being, above all, a compelling “year-in-the-life” tale of a group of ordinary, yet also extraordinary, teens. Whatever your take on their core views about guns, these kids’ stories are well worth hearing. They offer a vivid antidote to those worried we have raised a generation so hypnotized by the lower reaches of their phones’ capabilities that they are incapable of true connectedness and meaningful acts.

John Young teaches seventh-grade language arts and plays in the rock band The Optimists.

First Published: February 12, 2019, 2:00 p.m.