at this christmas time we remember 42,000 u.S. Troops still serving in afghanistan on this holiday. And abc's mike boettcher spent more than two years embedded with some of them and brings us now a report as part of an abc news special campaign. Home for the holidays. Reporter: Seana arrechaga and her 5-year-old are getting their home ready for the holidays. I actually was really excited to put up my christmas tree this year. Reporter: They have been living here less than a year before that fort campbell kentucky was home. With this man, his father, her husband. I think about him every day. I'll never forget thinking about him. Reporter: Army sergeant ofren arrechaga was stationed in afghanistan, my son carlos and i were embedded with his battalion when he and his comrades came under attack. One of the deadliest fire fights of the war. We remember that smile. Everybody does. Sergeant arrechaga one ofix killed. After, seana didn't want to live in their house any more, too many ghosts of ac, as everyone called him. Too many memories. I never wanted to leave that house. But I knew I had to. Reporter: We reached out to the charity homes for our troops, and they went to work. Providing this newly renovated home free of charge. It's huge. Being here is amazing. It's like starting over. Reporter: But this holiday season, that home, not the only gift for seana and her son. Reporter: This is sergeant mendez her husband's best buddy. I was a friend of your daddy's. Reporter: He tried to save him that day. This week he traveled to ohio to tell her something. I tried to get there as fast as I could. And I'm sorry that he didn't make it. Reporter: The gift of healing, and of living in the present. I'm going to watch my son grow up and put up the christmas tree for him every year and I'm learning to embrace life. Reporter: Mike boettcher, abc news, indianapolis.