Summer was fast approaching, and the students in British literature class had a breezy assignment: Analyze the comedic styles of “The Princess Bride.” A late arrival pierced the darkened room with a gun and a demand:

“Nobody move.”

Three seniors rose in defiance – of the order, of active shooter doctrine to flee, of basic survival instinct – and moved toward the gunman, as if in honed and practiced unison.

These new details emerged of the May 7 shooting at STEM School Highlands Ranch in suburban Denver in a Tuesday news conference with one of the seniors who rushed one of two shooters.

Joshua Jones, 18, told reporters there was not any kind of deliberation between himself and the other two students, Kendrick Castillo and Brendan Bialy, both 18-year-old seniors. All three acted nearly instantly once they realized a school shooter had a gun barrel pointed toward them.

“There wasn’t a whole lot that was going through my mind at the time. Adrenaline and tunnel vision are a crazy thing,” Jones said at a table, flanked by his parents, Lori and David Jones. “They make it so that you don’t really focus on anything but what’s right in front of your face at that moment.”

Each student had an improvised role. Castillo pinned the shooter against the wall. Bialy worked to get the gun away. Jones took the suspect to the ground.

Shots rang out. Castillo was shot and died of his injuries; Jones was shot twice in the left leg.

Jones had another priority as blood streamed from his gunshot wounds. Bialy helped retrieve his cellphone, and Jones held the shooter down on the ground while he dialed his mother’s number.

” ‘Hey, Mom. There’s been a school shooting,’ ” he recalled saying to his mother. ” ‘I’ve been involved. The authorities are on the way. They’re going to get an ambulance and I’m going to go to the hospital. That’s all I got right now for you.’ ”

Jones’s mother listened to her son recount the moment he dialed her number.

“I thanked him so many times for giving me a call, because I knew from the very first that my son was OK,” Lori Jones said. “I didn’t have the fear other parents did.”

Joshua Jones, a self-described lover of science fiction and fantasy, said he was learning to get around on crutches as he navigates the emotional “funk” left in the wake of the shooting, which also left seven other students wounded. “Physically, I’m recovering incredibly well. I’m healing fast. I mean, I’m a young kid.”

Authorities hailed the trio for their actions and have said their efforts minimized bloodshed. Castillo will be honored Wednesday in a memorial service on the same day the two shooting suspects appear in court.

Jones is preparing for a church mission trip after graduation, but the incident has prompted him to think of a career as a paramedic after encountering first responders. “I want to be able to do that,” he said. “I want to help those in need.”

But he acknowledged the pain of knowing Castillo could not follow another path. His friend was college-bound. Toward the end of the news conference, Jones explained the anguish of a choice and its result.

He was glad the students rushed the gunman, he said, but it came with a cost.

“It was truly a shame [Castillo] had to make that decision, and make a decision that led to his early . . . you know –”

Jones trailed off in search of the right word. He is a teenager, after all, who likely did not think of death much before it came to his literature class.

His father whispered a suggestion. Jones nodded.

“Early passing, yes,” Jones said.