They arrived in the damp mist of a North Florida evening, bedded down for the night on a civic center floor and awoke this morning prepared to deliver a message for their generation to the state's most powerful politicians.

"Our message is very simple," said Tanzil Philip, 16, a sophomore from Marjory Stoneman Douglas High School. "Never again. This never should have happened."

Philip was among the 100 students from the Parkland high school who traveled in a three-bus caravan to demand gun restrictions a week after the deadly shooting that left 17 of their classmates and teachers dead. It is the first official event of the student's #NeverAgain movement as they try to change gun and mental health laws in an effort to have their school be the last one riddled by a mass shooting.

"We are fighting for the kids we lost. We are fighting for the kids we're going to have," said Sophie Whitney, after the eight-hour drive. She and a busload of classmates were greeted late Tuesday by hundreds of cheering students at Leon High School, followed by pizza and ice cream.

They will carry their homemade signs up a hill to the Capitol on Wednesday morning, and embark on a marathon set of meetings with more than 75 legislators of both parties.

Read more: "Age limits and waiting periods for assault weapons? Florida legislators considering it"

"We're gonna keep talking, we're gonna keep pushing, until something is done — because people are dying," said Alfonso Calderon, a junior. "You guys are what we're trying to protect. We're what we're trying to protect. It's us."

Calderon said this school shooting was going to be different. "Change is gonna come now," he said, "and I want you guys to remember, this is never going to happen again like this."

And if they encounter legislators who don't want to listen?

Julia Bishop, 18, a senior, has an answer. She said said she will take down their name and "tell everyone I know … and the state of Florida … not to vote for this person," she said in a video posted by CNN during the bus ride. "And they'll be out of a job. I'm sure of it."

Bishop and her brother, Daniel, 16, said they came to Tallahassee to work for change.

"Even though I think there are responsible gun owners, there is no place for semi-automatic weapons to be held by civilians in our society," Julia Bishop said. "It was also about school safety and mental health."

They will meet with Attorney General Pam Bondi, Chief Financial Officer Jimmy Patronis, and Gov. Rick Scott, a favorite of the National Rifle Association, who has vowed that "everything is on the table" for reform.

Also meeting them will be key legislative leaders who have the ability to draft the specifics of a state law in the remaining 18 days of the legislative session.

Senate President Joe Negron, R-Stuart, and House Speaker Richard Corcoran, R-Land O'Lakes, say they are ready for them.

Before the students arrived, they and their deputies prepared a plan aimed at providing a comprehensive package of reform — from raising the minimum age to obtain and purchase an assault rifle from 18 to 21, to providing more school security officers, mental health counselors and a waiting period for the high-capacity guns.

Nikolas Cruz, the 19-year-old former student who returned on Valentine's Day to massacre his former classmates, had problems with mental illness. His classmates said the warning signs were there.

"I knew him from middle school," said Jaclyn Corin, the Douglas High junior class president who conceived of the trip to Tallahassee. "If there had been a 20-minute screening, maybe we wouldn't bee here."

Corin planted the idea for a trip to Tallahassee with Sen. Lauren Book, D-Plantation, and together they got it started. Book paid for the buses and meals. Sen. Wilton Simpson, R-Trilby, paid for the use of the Donald Tucker Civic Center, owned by Florida State University. And the media requests started rolling in. A Miami Herald photographer and videographer was on one of the buses. One network embedded a crew to do a documentary, and another scheduled live updates from the trip. National and international media had their cameras focused on the students as the buses arrived.

"When I started organizing this trip to Tallahassee, I had no idea if any of my classmates would even want to go," Corin wrote in a Tweet. "Now the world is watching."

" 'Be the change you wish to see in the world' — that quote is plastered high on a staircase in douglas," wrote Sarah Chadwick, in a Tweet just hours before the buses rolled from the Publix parking lot in Parkland. "I read it every day while walking to class, and now I'm here truly trying to be a change in the world."

The group will not take part in the rallies organized by gun control activists that will take place outside the Capitol Wednesday. Book said she encouraged them to stay away from the tense and politically charged events.

"These kids are fragile, and I'm just scared," she said. Instead, she has lined up grief counselors to be available from Leon County schools in case something triggers the trauma again for any of the students. "These kids are eloquent, but we want to provide them with some space, too," she said.

The long drive was punctuated by a stream of news as students kept up on their phones:

The Florida House of Representatives refused to take up a bill to ban assault weapons.

Actor George Clooney and his wife donated $500,000 in the name of their children to help finance the March For Our Lives event in Washington, D.C. on March 24. Then so did Oprah Winfrey. And Steven Spielberg.

The mayor of Dallas told the NRA to find another city for its May meeting unless it supported changes to gun laws.

Each of the developments prompted many of the students — who have now attracted thousands of Twitter followers as leaders of a burgeoning social movement — to comment with their own Tweets.

At the rest stop, student Diego Pfeiffer recorded a video comparing the slavery and suffrage movements to their cause. "The good always wins,'' he said. "You're either with us, or against us."

Ryan Deitsch, 18, said he attended a friend's funeral just before getting on the bus, and his goal is to do "literally anything just to change the world for the better."

When they arrived, the students were escorted to the Leon High School cafeteria, which had the feel of a long, crowded sleepover, as students scarfed down pizza and ice cream and hugged friends who had come in on different buses.

But the hugs lasted a little too long, and the adults spoke a little too softly and gently. Everywhere, people patted each other's backs or squeezed shoulders, almost to remind each other that this was all really happening.

Next to the boxes of food, some of the girls picked out painted rocks with inspiring messages: "You are strong," "Lift others," "Bloom where you are planted." One read simply: "Heal."

Along the back wall, friends Sarah Brodsky and Beni Gross, both 16, recalled how long ago Wednesday morning felt. Sarah had been worrying about her pre-Calculus test. Beni had hoped she would get a carnation for Valentine's Day.

Instead, they spent that afternoon in a panicked haze. Brodsky hid in the JROTC classroom when people started screaming and running from the sound of gunshots. Gross thought it was a fire or another drill when she sprinted with classmates back into her own classroom, waiting inside with the lights off. Neither realized how devastating the shooting was until they were evacuated from the school and texts from terrified friends and far flung family flooded their phones.

Gross said when she used to introduce herself at summer camp abroad, she'd tell people she was from Miami or Boca Raton. "If I said Parkland, people are like, 'What's that?' " she said. "Now everyone knows what Parkland is, it's just crazy."

"For such a good community to have such a bad reputation now …" Brodsky's voice trailed off.

"But really," Gross said, "they're going to see Parkland comes together and is strong and united and makes change."