DALEVILLE — He didn’t know what he had done wrong, but third-grader Nicholas Carlson thought he was in trouble Friday when he was called to Principal David Stashevsky’s office at Daleville Elementary School.

As he slowly walked into the office, Nicholas’ eyes widened when he saw who was waiting for him around the corner.

“Mom!” he shouted as he jumped into her arms. “You sure did surprise me!”

Nicholas’ mother, Dawn Carlson, had just returned from her second deployment in Iraq the night before, having been away from her son since last February.

She thought a lunchtime surprise at school would be the best way to reveal she was home indefinitely, after her flights had been bumped several times and her arrival date kept changing.

“He’s just really anxious,” Carlson said. “A lot of the families were upset. That’s why I never told him.”

After a year apart — except for a four-day pass Carlson received in April — mother and son spent several moments hugging and kissing each other before heading off to lunch in the cafeteria together. On the way out the door, Nicholas said his mom coming home was the best day ever.

“I was totally surprised,” he said. “I was like, ‘Oh my gosh, how is she here?’”

Nicholas knew his mother was coming home soon and that it would be a surprise when she did. He was so anxious awaiting her return, he pretended to be his father on the phone while talking to her, trying to coax it out of her when she would be home.

“I feel much better,” Nicholas said, as he and his mom caught up with each other over chicken sandwiches, cookies and chocolate milk. “I don’t think I can let go of her.”

The two had talked on the phone and over Skype, an Internet-based web camera program, during Carlson’s deployment, in which she was based in Rustamiyah, Iraq, as military intelligence with the National Guard.

Before that, she had been in Kuwait and at Fort Dix, N.J., as a sergeant with the 38th Military Police Company.

“It’s hard,” she said about being away from her family. “It’s really hard. All you can think about is your kids and call as much as you can and write and put pictures up all over my walls.”

Carlson also has a teenage daughter, Carissa Tompkins.