On Tuesday morning, the body of the sixteen-year-old Carmen Schentrup was laid to rest in an Episcopalian ceremony at the St. Andrew Church in Coral Springs, Florida. In his sermon, the Reverend Canon Mark H. Sims remembered Schentrup, who liked teal handbags and red lipstick, and who wrote notes on her piano sheet music to remind her where she had left off. At a nearby funeral home, a wake was being prepared for the fifteen-year-old Peter Wang, who was also killed at Marjory Stoneman Douglas High School on February 14th. The child of Chinese immigrants who owned a restaurant in West Palm Beach, Wang had wanted to join the military. His fellow J.R.O.T.C. members served as his pallbearers, and West Point posthumously granted him acceptance into the class of 2025.

On Tuesday afternoon, in a parking lot outside a Publix supermarket on Coral Ridge Drive, three white charter buses awaited the arrival of a hundred Stoneman Douglas students and their fifteen adult chaperones, who were travelling to the state capitol in Tallahassee to advocate for stricter gun-control laws. The students arrived carrying sleeping bags, pillows, and permission slips signed by their parents. The media besieged them with questions. A helicopter hovered overhead. Two women wearing the uniform of the nearby gas station stood next to one of the buses. I asked if they were parents. No, they said, but the students were their customers. “We know all of them,” one said, and they wanted to support them.

I approached a student in braids holding an overnight bag and sign that said “ENOUGH.” Her name was Tyra Hemans, and I watched her argue with a reporter about the likelihood that anybody in Tallahassee would change gun laws. “This law does not deserve to take lives anymore,” she insisted, without specifying a law. “It is a law that takes lives, it is a murderous law. It is a dirty law. I’m getting rid of the law.” After the reporter moved on, I asked why she was there. She told me about her friend Meadow Pollack, with whom she shared a birthday and a love of rap music.

Further Reading New Yorker writers respond to the Parkland school shooting.

Another student, a Never Again organizer named Chris Grady, stood to the side, observing the scene. A slim figure with curly hair, Grady, I had been told by other organizers, would be joining the Army after graduation. I asked if there was a contradiction between advocating for gun control and becoming a soldier. “Not at all,” he said. “These AR-15s, they’re weapons of war. Going to school, you’re not going to war, you’re trying to get an education.” After the Army, Grady wanted to pursue a career in politics. He admitted to feeling “apprehensive” about leaving behind the movement he’d helped galvanize when he ships out in June.

The organizer of the trip, the junior-class president, Jaclyn Corin, rushed between buses, holding lists that assigned seating, and turning down interview requests with an in-motion “I can’t.” Small and blonde, she wore a Stoneman Douglas windbreaker, black leggings, and brown ankle boots.

The young activists had stayed up late yet again the night before, in their unofficial headquarters at the house of Cameron Kasky, a student co-founder of the Never Again movement. “I was with Jackie all night making these bus arrangements,” a junior named Dylan Redshaw said. “I was on my phone on Snapchat crossing off the names because [Cameron’s] printer is broken. It’s been broken for, like, five days.” Kasky was in the parking lot, too, wearing a Stoneman Douglas warmup jacket. He and Corin climbed up to the car to make announcements and offer advice.

“Guys, over the next couple of days there are a lot of people who are being paid a lot of money to ruin what we are doing,” Kasky said. “A lot of people with cameras here are here to help, and a lot of people with cameras here are here to destroy us and to keep the Second Amendment safe. First of all, we’re doing that, too. I want my dad to keep his guns. We’re just trying to just not let seventeen of us get shot in the fucking face again.”

“Amen!” someone yelled in the crowd.

The leaders of the Never Again movement had started attracting the derision of some members of the right wing. On Tuesday, in Florida, an aide to a Republican state representative was fired for e-mailing a reporter to float the theory that the student activists were paid actors. Kasky suspended his Facebook account because, he said, unlike Twitter, “there’s no character count, so the death threats from the N.R.A. cultists are a bit more graphic.” The student tried to joke about some of the more egregious social-media conspiracies: that their classmate David Hogg was an F.B.I. plant, or a twenty-six-year-old felon from California.

Corin called out the names of the students who belonged on each bus, and they boarded. Kasky embraced Corin and Grady in a three-way hug; Kasky was staying in South Florida, to coördinate a CNN town-hall meeting the following day. The photographers in the crowd moved their tripods to record the exit of the bus fleet, but the buses didn’t leave. The air-conditioner on one had failed. A replacement was ordered, causing a delay.

I stood and chatted with Paul Corin, Jaclyn Corin’s father, who had taken the day off work to wish the students goodbye. (Jackie’s mother, Maryleigh, was one of the chaperones.) “I’m staying to feed the dog,” Corin said. He and Maryleigh watched as Jaclyn ran between the buses, the lists still in her hand. She paused for a moment before her parents, tearing up in frustration. “It’s just that everybody’s depending on me,” she said to her dad. “You’re good,” he told her, with a pat on the arm. She rushed away again, climbing the steps of the malfunctioning bus, on which students were popping open the ceiling vents. The first two buses departed shortly before 2 P.M. The one with the broken air-conditioner was replaced just over an hour later. Corin rode on the last bus.

After the first two buses departed, I went to Marjory Stoneman Douglas High School. The roads around it, which had been closed since the shooting, were now passable. The school is in fact a campus of several white buildings with red terra-cotta tile roofs. (The shooting had been in what students call the freshman building.) When I arrived, a small crowd of young people were milling around on the corner of Coral Springs Drive and Holmberg Road, some of them in black funeral wear, having come from funerals. An ambulance pulled up to treat a student who, apparently suffering from heat stroke, sat on the street corner. I walked up to a group of teen-age girls to ask what was going on. They were wearing maroon and white, the school colors of Stoneman Douglas, and it wasn’t until one student, a fifteen-year-old sophomore named Catherine Silva, started telling me why they were there that I realized that they were from another school, West Boca Raton High. That morning, Silva told me, their school had held a seventeen-minute silence for each of the students and staff members who had died in the shooting, after which a spontaneous protest had erupted: a thousand of the students had decided to leave school, and they had simply kept walking the twelve miles southwest to Marjory Stoneman Douglas High.

“Everyone started leaving the gates of the school, and people were trying to prevent us, like, assistant principals were trying to tell us, ‘No, no, no, go back,’ so we just stampeded through the gates,” Silva told me, a note of elation in her voice. “I think I was one of the first people who was, like, ‘We’re walking to Marjory, we’re walking to Marjory Stoneman Douglas High School. We’re going. We’re walking all the way there.’ ”