When he was growing up, recalls Julian Borger, it felt as if his family “had painted layer after layer of tasteful off-white over the top of something garish, more visceral and unsettling”. His difficult and dissatisfied psychologist father Robert had never managed to overcome “the refugee’s curse” of being “from two places and none at the same time”. His grandmother Erna, when invited over, “would typically arrive late and… insist on making Viennese food from scratch, unpacking her plastic shopping bags on the already set kitchen table”.

The rest of the family knew that Erna and the 11-year-old Robert, Viennese Jews fleeing Nazi persecution, had arrived in England in October 1938. She had been granted a visa to work as a maid, while he was adopted by Nancy and Reg Bingley in Wales. But further details, never mind the emotional impact of such dislocation and separation, were shrouded in silence.

Then in 1983, when Borger was 22, his father took his own life. Most people assumed that he had been driven to it by money troubles and a sense of failure, but Nancy Bingley had a disturbingly different interpretation: “Robert was the Nazis’ last victim. They got to him in the end.”

For a long time, Borger tried to put such family ghosts behind him. He left England and has worked for the Guardian all over the world. But then a chance encounter reminded him that, in 1938, his grandfather Leo had placed a brief notice about Robert in what was then the Manchester Guardian: “I seek a kind person who will educate my intelligent boy, aged 11, Viennese of good family.”

There were about 80 such advertisements in all, he discovered, hidden away among crosswords and radio schedules. Borger was deeply affected by these poignant “appeals from frantic parents trying to save their sons and daughters, all within the space of an epigram. It was impossible to read them without needing to know how these stories unfolded.” His powerful new book reconstructs what happened to seven of the children.

Some, inevitably, failed to escape from continental Europe and got caught up in what Borger calls “the maw of the Nazi murder machine”, but others had very different experiences. Gertrude Langer came to England but then discovered that her parents had managed to get to Shanghai. When she reached the Chinese city, she found that new arrivals had already created a “Little Vienna” of restaurants and cafes. But this idyll proved short-lived. The Japanese signed a pact with Germany, sent their troops in and confined the Jews to a tiny ghetto on starvation rations. Fortunately, Gertrude and her new husband Ted were able to secure passage to the US, though the exchange rate was so bad they had to hire a rickshaw to deliver 27m yuan in 10-yuan notes to the shipping company.

George Mandler also made it to the US but, in 1944, returned to Europe as part of American military intelligence. He took great pleasure in extracting information from captured German soldiers, sometimes by threatening to turn them over to the Russians. His team helped evacuate leading scientists and even acquired a French chef who commandeered the best wine from stately homes.

His research also uncovered more about Borger’s own family history. He had known his great aunt Malci only as a sad old woman ending her days in a tiny Viennese flat. Yet her earlier life had been full of drama. She had married a communist activist and probable Bolshevik spy who was deported from France and disappeared without trace, leaving her with two tiny stepchildren. She spent much of the second world war hidden in a French convent, while her stepson Mordechaj was a leading member of the highly effective Austrian Jewish resistance and carried out extremely dangerous work, infiltrating Nazi institutions such as a major steelworks.

There have been quite a few books about Viennese Jewish lives before and during the second world war, but Borger offer us a compelling range of accounts “twined together through the tiny coincidence of a newspaper ad and then diverging in all directions as a bloom of dazzling colours”. He was particularly thrilled to find that one of the children, Lisbeth Weiss, was alive at the age of 91, with “memories still intact of the world my dad had been born into, the place I had been straining to imagine”.

More important, Weiss taught Borger something about his father’s emotional landscape. Though she had worked in Holocaust education, she had also been careful to maintain a careful balance between dwelling on traumatic memories and avoiding them altogether, he reflects, since “the past can trap you if you spend too much time there, or control you if you spend too little. Floating between the two is some sort of freedom and happiness. It is a place our dad did not manage to find.”

Writing his book, Borger concludes, unearthed feelings of “resentment” towards his father “but also brought its antidote” in the form of deeper understanding. It makes a gripping addition to the literature on inherited trauma.

• I Seek a Kind Person: My Father, Seven Children and the Adverts That Helped Them Escape the Holocaust by Julian Borger is published by John Murray (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply