The movie theater just up the road had long served as a hangout for students from Gateway High School, and they had a habit of treating the place as if it were theirs. They threw water balloons in the parking lot, flirted in the ticket lines and sneaked in beer in the pockets of their cargo shorts. They were the theater’s most loyal customers. A purple-and-black banner for their school occasionally hung in the lobby.

Dozens of students and recent graduates arrived for the Batman premiere late Thursday night, and their attendance transformed a cookie-cutter megaplex amid the suburban sprawl of Aurora into a familiar community. “The Dark Knight Rises” was playing in four theaters after midnight, and students walked freely from one to the other before showtime, exchanging fist bumps and trading tickets to sit closer to friends. A running back on the football team was supposed to be in Theater 8 but sat instead in Theater 9. A 2010 graduate left her seat in the back row to join friends near the front.

They acted like teenagers at a midnight premiere, tossing candy wrappers across the rows, texting friends in the theater next door and making loud jokes during the previews. But they were also preoccupied with their own lives in transition. Jennifer Seeger, a Gateway alum who had just moved out of her parents’ house and into her own apartment, arrived late and sat in the second row of Theater 9. Earlier in the day, she had taken a certification test to become an Aurora firefighter, devoting three hours to multiple-choice questions about what to do in an emergency. She texted a friend as she arrived at the theater: “I better have passed.”

Several rows behind her, Seeger noticed A.J. Boik, a wispy Gateway grad who was headed to art school and had recently become engaged — even though he hadn’t yet mustered the courage to tell his parents. Behind him were several members of the Gateway football team: both starting running backs, the tight end and star offensive lineman Zack Golditch, 17, impossible to miss at 6-foot-4 and 260 pounds with a blond mohawk. Golditch, a junior, visited with friends, drank a bottle of 5-hour Energy and eventually walked over to Theater 8 to join more of his Gateway classmates.

There was something else that connected all of them: They had grown up and attended public school in the age of Columbine, in the place of Columbine, just across town from the high school where two gunmen killed 13 people and themselves in 1999. It was the massacre that ushered in a new age of mass shootings and redrew the childhood boundaries of the students now waiting for the movie to begin. Most of them didn’t remember the specifics of that day — they were only 5 or 6 years old — but its evidence had been all around them as they grew up.

It was the photos in their modern U.S. history textbooks of news helicopters circling the high school and grieving teenagers standing at a flowered memorial. It was the Gateway security guards who patrolled the parking lot in white SUVs, a gun at the hip of each gray-and-black uniform. It was the statewide school safety hotline that was advertised on fliers in the hallways; and the bomb threat that had closed an Aurora school some years earlier; and the annual “Code 3” lockdown drill, in which they barricaded themselves inside classrooms, taped black construction paper over the windows and scrambled into the corner farthest from the door to sit in silence for five minutes.

Their Gateway teachers had led classroom debates about gun-control laws and violence in Hollywood. The teenagers had spent even more time debating rules and boundaries inside their own households, with parents who had been trained to see risk in every public space.

Christine Golditch was one of those parents. When her son, Zack, the offensive lineman, had explained Thursday afternoon that he planned to see a movie at 12:01 a.m., she sat with him in the living room and peppered him with questions. Who else was going? What was the running time? Who was driving? How would he wake up for football practice in the morning?

Zack had sat on the couch and listened impatiently. He was an incoming senior with a dozen school weightlifting records, a serpent tattoo on his bicep and a scholarship to play football at Colorado State University. Sometimes he thought he was too old for his mother’s worrying.

“Mom,” he had said, making his final case, “it’s just Batman.”

A new terror

And then the latest mass shooting began, redefining life in these Denver suburbs once again.

When the gunman entered the theater 20 minutes into the movie through an emergency exit to the right of the screen, it was a former Gateway student who was closest to him: Seeger, the aspiring firefighter, sitting in the second row. He threw a gas grenade that hissed over her head like a can of fizzing soda. Seeger dove instinctually to the polished concrete floor between the first and second rows — all those lockdowns, all that emergency preparedness rushing back.

Stay low.

She crawled under her seat and started moving to her left, away from the shooter, taking measured breaths to stave off her asthma.

Keep quiet.

She covered her mouth with her T-shirt and pressed her nails into the floor to keep from yelling when hot shell casings fell and burned inch-long scars into her legs.

Be aware.

The gunshots stopped for a few seconds, and Seeger climbed onto her knees to look back across the theater. There in the dark, amid the shots, screams and blaring movie soundtrack, some of her friends and former classmates were trying to survive.

DeVonte Brock, an 18-year-old Gateway grad, grabbed his sister and two Gateway football players and jumped over two rows of seats toward the rear exit. His sister turned back for her jacket, cellphone and purse. “Forget that stuff and move!” Brock yelled.

Next door, sitting in the center of Theater 8, Golditch heard a series of muffled explosions in the theater to his left. “Probably jackasses throwing firecrackers,” he told his friends before turning back to the movie. Then he felt a bang in his left ear that knocked him into a friend’s lap. His shirt turned red with blood. He reached his hand up to his ear. There was a hole in his neck about the size of a quarter, from a bullet that had come through the partition.

Back in Theater 9, Seeger crawled toward the exit to make her escape. In the aisle on the right side of the room was the body of a young man with a mustache. She thought he looked like Boik, the Gateway graduate who had come to the movie with his new fiancee, but it was too dark to know for sure. Seeger dragged the man toward the exit. “Leave him!” a friend shouted. Seeger tried to find a pulse, placing her fingers on a wrist that felt lifeless. Then she followed her friend out of the theater.

Gathering to grieve

The Gateway students and graduates gathered again over the weekend for Boik’s memorial on the football field at the high school. Some athletes came in purple-and-black jerseys as a show of solidarity.

Golditch arrived with a bandage covering the entry and exit wound under his left ear. “Just got a little muscle,” he said.

Seeger came with bloodshot eyes and smudged black mascara, a little less sure that she wanted to spend her career responding to emergencies.

Boik’s fiancee handed out remembrance candles to the crowd. A dozen Gateway classmates took turns talking about Boik, remembering a friend who had spoken in a fake Italian accent, posted video of his ridiculous dance moves on Facebook and painted pupils on his eyelids just to make a girl laugh. The mourners said a prayer and released hundreds of balloons into the Colorado evening sky, watching them dis­appear over the school and into the distant foothills.

“You can leave something here for A.J. if you want,” his fiancee said.

One by one, they dropped off their offerings: flowers, photos, T-shirts, poems and notes, until a small pile grew on the side of the high school track. News helicopters circled above. Police patrolled nearby. Teenagers bared their scars and shared in a grief that was searing and intimate and yet somehow familiar.

Thirteen years later at another Colorado high school, a new memorial began taking shape.