In late June, Navy SEAL Kevin A. Houston, a 1994 graduate of Barnstable High School, was visiting his surrogate father, Christopher Kelly of Osterville.
"Oh, wait a minute," he said to Mr. Kelly, who served in the 101st Airborne Division in the Vietnam War. "I've got something for you."
Mr. Houston went out to his car and brought back an American flag wrapped in a square, and a letter.
The letter gave a history of the flag: Mr. Houston had worn it between his chest and his body armor in all three of his deployments in Afghanistan.
In those deployments, he had worn the flag on more than 100 capture/kill missions that resulted in 650 enemy killed in action and 300 enemy detained.
Mr. Houston also was wearing the flag on the mission when one of his best friends was killed.
"I carried this flag for you from the beginning," he wrote in the letter to Mr. Kelly. "I'm honored to hand this to you."
By early this month, Mr. Houston, a special warfare operator chief petty officer, was back in Afghanistan on his fourth deployment.
Then, this past Saturday, Mr. Houston was riding in a NATO Chinook helicopter on a mission above the mountains of eastern Afghanistan when the aircraft was shot down, killing him and the other 37 people on board, including 21 other Navy SEALs. He was 35.
The Taliban claimed responsibility.
"He was doing what he always wanted to do, defending the country as a SEAL," Mr. Kelly said Tuesday. "He achieved his dream."
From an early age, Mr. Houston had no doubt about what he wanted to do with his life.
"Hi, I'm Kevin," he told a fellow 5th grade student sent to greet him on his first day at Hyannis West Elementary School. "I'm going to be a Navy SEAL."
In 1999, he became a SEAL. The acronym, which stands for "Sea, Air, Land," designates the Navy's principal special operations force. The acronym is derived from their capacity to operate at sea, in the air, and on land.
During Mr. Houston's military career, he would be honored with two Bronze Stars and a Purple Heart among other commendations.
He also had no doubt about how to live his life.
"He was driven, he was selfless," said a longtime friend, Joe Kennedy, 35, of Osterville, who greeted him that first day at Hyannis West.
"He was just larger than life," Mr. Kennedy said. "He was funny, gregarious.... He wanted everyone around him to feel good. He loved the underdog. He enjoyed life. He loved his family.... He was loyal beyond description."
Mr. Houston's mother, Janette Brown of Chesapeake, Virginia, also describes him as "larger than life."
"He was everyone's friend," Ms. Brown said Tuesday. "He never met a stranger."
"He hit the ground running and he didn't stop till the other night," she said.
Another longtime friend, Kevin MacConnell, 33, of Hyannis, said he was impressed that Kevin Houston would never get too high when things were going great or too low when they were not.
"He had that at a very young [age]," Mr. MacConnell said.
Ms. Brown describes her son as "an adventure to raise." She knew she was going to have her hands full when she found him climbing out of his crib at the age of 8 months.
He would go on to excel in athletics, a football team co-captain on the Barnstable High varsity football squad who played middle linebacker. Mr. Kennedy remembers his play as "ferocious."
Mr. MacConnell also recalls Mr. Houston as someone who "transcended" cliques at school.
Mr. Kennedy said: "He just got along with everybody. He was a large presence socially.... People were just drawn to him."
Another longtime friend, Ty Herron, said, "He would never look down on a person unless it was to give him a hand to help him up."
High school also is when Kevin Houston got to know Christopher Kelly.
"He was about 17," Mr. Kelly said. "He was dating my daughter.
"He was thrilled to meet a Vietnam veteran," Mr. Kelly said. He asked Mr. Kelly if he had any pictures from his service, and when the veteran said yes, he had an album, the young man pored over the photos.
"He asked to see it every time he came over," Mr. Kelly said.
Their bond grew.
"I was a surrogate father," Mr. Kelly said. "I'd hug him like a son. He was a kid to me."
In the spring of his senior year at Barnstable High, Mr. Houston was involved in a motorcycle accident on Church Street in West Barnstable. The accident broke a bone in his back and left him in a wheelchair for graduation.
Ms. Herron pushed him in the chair out onto the high school field for the ceremony. But she remembers how he got up to walk across the stage to accept his diploma.
By the following year, he had passed his Navy physical and was able to join the service.
Mr. Houston subsequently moved to the Chesapeake, Virginia, area, as did his mother and the rest of his family.
The Chesapeake area also is where Mr. Houston based his own family: his wife, Mei Ling, his sons, Michael and Ethan, and daughter, Jana.
When Mr. Houston's younger sister, Miranda, was diagnosed with ovarian cancer, he visited her.
His presence immediately enlivened her, their mother recalls. "Will you take me to Taco Bell?" Miranda asked her brother.
Miranda lived for another year before dying in 2005. "He described her as being a Spartan warrior," Ms. Brown said.
A memorial service for Mr. Houston was held yesterday afternoon at the Atlantic Shores Baptist Church in Virginia Beach.
He will be buried at Arlington National Cemetery.
Mr. Kennedy and Mr. MacConnell plan to organize a memorial service for Mr. Houston at a future date on Cape Cod.
The flag that Mr. Houston gave Mr. Kelly, meanwhile, remains wrapped as it was the day in June that the SEAL gave it to him.
Mr. Kelly has been pricing flagpoles.
"I hope you let her fly in the backyard," Kevin Houston wrote him in the letter, "and have a toast now and then."