The moment I saw my face on the side of a milk carton, with the caption “Missing”, I realised that most of my childhood had been a lie. I was 13, and it was 1983. My parents had separated when I was two. It was amicable, but my mother and I lived in Norway, and my father was American. He wanted to go home, and became convinced I would be better off living in the US with him.

When I was four, he came to take me out for the day, telling my mother we’d be back at 2pm. We never returned. Instead, we flew to America. I remember being on a plane and feeling excited that we were going on an adventure. At first, my father said my mother was coming to join us; but the weeks passed and he began saying that she didn’t want to come after all. Soon, I found myself believing the negative comments he made about her. Little did I know she was desperately searching for me.

I converted to my father’s religion of Judaism and was given a new name, Sarah (I had been born Cecilie). We travelled through 34 states, and for a while lived in Canada and Mexico. My father would go to synagogues with letters from rabbis saying it would be a mitzvah, a good deed, to help him – and people did, opening up their homes to us. He occasionally did fundraising for schools, but never had a proper income.

We were always looking over our shoulders, moving on every few months. Interpol and the US police were looking for us, as were detectives hired by my mother. Occasionally, people became suspicious of this man alone with a child, and called 911. We had several close calls, but we were never found. We often changed our names: for a while, when I was aged eight, my hair was cut short and I pretended to be a boy called Max.

We stayed with a few families again and again, so I did forge connections. One woman was a mother figure who helped me with things like getting my first bra. My relationship with my father was strained. He was a very difficult man and I learned to read signals and stay out of his way. But I felt loyal to him, and after a while I couldn’t remember my mother. He told people she was dead, or an unfit parent. I felt abandoned, and confused, so I, too, began to tell people I didn’t have a mother.

The day I saw myself on a milk carton changed everything. We were staying with a family in the midwest at the time. In secret, I cut out my picture and kept it. I started looking at my father differently, questioning everything. It took three more years for me to act, but at 16 I left and went to live with a family I knew in New Jersey. My father knew he couldn’t go to the police.

My mother had kept her married name, Finkelstein, to make it easier for me to track her down – which I did, aged 17. I called and said, “Hello, this is your daughter.” There was a silence, and then she replied, with a sad voice, “Are you OK?”

I was 18 when we met in New York, on 4 July. Fireworks were going off, but it wasn’t happily ever after. It took a long time for us to connect. She hoped I’d move to Norway, while I needed space to get to know her. Now, she still lives in Norway, but is very involved in my life, and with her grandchildren, my sons Aidan, nine, and Daniel, five. My father was never punished: no one wanted to press charges at the time, and by now the statute of limitations is long over.

In 2012, I went to Jerusalem, where my father now lives. I wanted to hear his side, and for him to be part of a documentary about my story, called Sarah-Cecilie. The first thing he said to me was that he had the right to travel with his child. He never uses the term abduction, and says that I grew as a person by travelling with him. We have stayed in touch; he is old and infirm now.

I have battled depression over the years, but my husband has helped me recover. I’m not angry with my father. I know he must have had severe issues to have done what he did. Now I have found not closure, but peace.

• As told to Eleanor Tucker. The film Sarah-Cecilie is out this week; go to pact-online.org for details.

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