In 1946, Serraillier published his first two children's books: "They Raced for Treasure", a story of sailing, treasure and spies, and "Thomas and the Sparrow". These were followed by several more adventure stories, including his best-known "The Silver Sword" (1956), which follows the story of four refugee children, three of them siblings: Ruth, Edek, and Bronia. The fourth, Jan, is another of the many Warsaw war orphans who has somehow met their father. He then fainted near the bombed-out basement that serves as the siblings' home. The four join together in their search for the siblings' parents in the chaos of Europe immediately after the Second World War. The book was published in the United States under the title "Escape from Warsaw".