As the Great Patriotic War broke out, Frayerman joined the Red Army volunteer corps. In January 1942 he was seriously injured and in May demobilized. In 1946 his novel " Long Sea Voyage" (Dalneye Plavaniye) came out, followed by "The Life and Extraordinary Adventures of Captain-Lieutenant Golovkin" (1948, with P.Zaykin as a co-author), a biography turned into a thriller. Among Frayerman's later books were "Children's Best-Loved Author" (Lyubimy Pisatel Detei, 1954, on Arkady Gaidar) and "A Test for Soul" (Ispytanye Dushi, 1966), the collection of sketches and essays. Ruvim Frayerman died on 28 March 1972 in Moscow. He was buried at the Pyatnitskoye Cemetery.