Twice a day, every day for almost a month, Angie Kim and her two – year – old son entered a hyperbaric oxygen tank and were sealed inside. Kim's son was suffering from ulcerative colitis, a condition that was very painful, and constant vomiting had left him under the weight. According to the theory behind hyperbaric oxygen therapy (HBOT), if damaged cells need oxygen to heal, immersing a patient in pure oxygen will accelerate healing. Although the experimental treatment was not approved by the FDA and has no proven benefit, it was a last resort that Kim was willing to try.

His son described the tank as "the submarine", and it was not far off: when the hatch was closed, the space dark and warm, lit only by flickering episodes of Barney and Sesame Street outside the portholes, could have been almost under water; Kim, 15 years later, likens this to a confession. While the children were watching television, bored parents and parents, wearing only cotton clothes and freeing their potentially flammable glasses, underwired bras and belts, began to talk.

There, Kim found a window on the lives of other peoples. One of the children was a stool scrubber, which could interrupt a "dive" when they asked for the tank to be cleaned, which could trigger another one, which would hit his head against the wall violently. She began to feel guilty: even though her son was in pain, the other children were mostly severely autistic or disabled and for their parents, the OTHB was a punch in the dark for children who could not neither walk, nor speak, nor hug each other. "I have always considered myself and my family as unlucky," says the 50-year-old author. "This son was also deaf in one ear and suffered from celiac disease. My other son had anaphylactic food allergies. I could not work because of all the CT scanners, MRIs and cooking specialties that I had to do. So, I felt really sorry for ourselves until I met these families, who were so optimistic. It made me have a totally different view of life, the relativity of happiness. "

His first thriller, Miracle Creek, focuses on this relativity and the explosion of a HBOT tank, which wounds many and kills two, one being Henry, a severely autistic boy. As shark-like lawyers discover new details, the characters go from "hero to murderer in an hour" and the truth becomes less and less clear as gossip spreads around the small town. But for Kim, the blast was "a Trojan horse, a MacGuffin" that allowed him to explore deeper issues: the identity crisis among migrants in the United States, the realities of severe autism and chronic diseases, and extreme parental sacrifices.

Of these, there are many. Elizabeth, who may have killed her son Henry, is judged but released from a responsibility she feels more and more. Teresa, nicknamed Mother Teresa for her clean image, wants the trial to last longer because it gives her time to get away from her daughter. And Pak, the owner of the HBOT tank and a "father of goose" – a South Korean phenomenon where patriarchs send their children and their wives abroad while saving money to migrate also. He feels "the shame of becoming less competent, less adult, than his own child," Mary, a teenager who serves as a family translator and who despises more and more her two parents.

Kim's father was neither a goose nor a penguin (the latter being the ones who can not afford a short annual visit like this). The family left Seoul together to travel to Baltimore, a suburb, at the age of 11. In Korea, a teacher had asked students to name themselves class president. Kim was the only girl to have raised her hand and the teacher slapped her with a ruler in front of the class, "for daring to think that girls can be president of any matter. Korea is a very male dominated patriarchal culture, where it is essential to have sons. When my mother heard that she was so angry and I think it was an important motivator for the move. Ironically, Korea had a woman president before the United States. "

Upon arrival, Kim lived with her aunt and uncle, while her parents ran a grocery store downtown, where they slept too, between cans and food in the back room. Kim, an only child, displeased their sacrifice. For the first time, she had her own bedroom and plumbing – but no parents. "I accused them of abandoning me. We were so poor in Korea, so coming to the United States was a chance. But I was very sorry to lose touch with my parents, so I acted. "That's only 40 years later, writing to Miracle Creek, that she acknowledged that it was a sacrifice:" You would think after law school and the children of my clean that I would have let go. But we never talked about it. The writing made me think about what it had been for them. I realized that I had been a kid. They read it and we had a really cathartic conversation. This is the best thing that came out of this novel for me. "

Angie Kim

"I felt really sorry for us until I met these families, who were so optimistic" … Angie Kim. Photography: Tim Coburn

Before having her own children, Kim worked as a lawyer at the trial. She loved the drama but hated the machismo of the audience room. After a busy period, she took a brief break in San Francisco; She went to an empty cliffside restaurant and spent the whole day there, alone with a bottle of wine and a plate of cheese, and read Tim O'Brien's cover in Lake of the Woods. "When I closed it, I did not remember being so happy, that day I decided to resign." Even though she would later become an Internet entrepreneur, then would stay home for her sons for a decade, she decided to be an author that day.

Decades later, with her first book to her credit, she finds herself alongside migrant writers, notably Ocean Vuong and Viet Thanh Nguyen, who write in the United States about themselves, both in fiction and film. In fact, the three have recently signed a star-studded letter calling for an end to inhumane conditions in detention centers on the US-Mexico border.

In the United States, the perspective of migrants is crucial because "we are like a very close friend who loves you, but who can also tell you what you need to hear. Migrants have the responsibility as people who have chosen to come to this country to bring this perspective, to make us stronger. I do not agree with the argument that we should be grateful or quiet and "go back to the beginning". "

With regard to Trump's recent racist comments, she remembers a puzzling two-month period when she first arrived in the United States, during which she finally figured out enough about her. To know that other children were making fun of her, of her appearance, of her smell, but without answering her. "I became grateful to finally understand and then feel terrible because these seemingly nice kids have been making fun of me all the time. When I hear Trump say, "Go home," it takes me 40 years back. I speak fluently, I succeed, I went to good schools. And all these things, just hearing that happen to someone else, make me cry and make me feel like I do not belong, even today. "

Miracle Creek by Angie Kim (Hodder & Stoughton, £ 16.99). To order a copy, go to UK free p & p on all online orders over £ 15.