K. and Inge finally left Berlin in 1933, as Hitler's Brownshirts took over the city. They moved to Lisbon, Portugal where Inge has relations. Exile in Portugal separated Ungeheuer from his friends in the publishing world. Even though he continues writing regularly, he ceases publishing by the mid '30's.
Ungeheuer earned a living in Portugal teaching mathematics. He also developed his Numerolingual theory, exploring the relationship between math and language. In 1950 an old friend of Willem Schultz tracked K. down to request the manuscript to Dein Gesicht ist Meine Geschichte. It was published in Germany in 1951, 20 years after its original date for publication.
In 1958 K. and Inge followed acquaintances from Lisbon to New York City. Ungeheuer met Jacob Marsteen there in 1964. Marsteen ran a small magazine called The 10 cent Gutenberg (it cost only five cents). He was also a very enthusiastic fan of this practically unheard of author. Through Marsteen's influence Ungeheuer started publishing again. Although he could speak and write in German, English, Portuguese, and Spanish, he insisted on writing entirely in German. Through management provided by Marsteen, Die Kunst des Mittelalters [The Art of the Middle Ages] is released in 1967.
Jacob Marsteen drowned in 1972 at a weekend party in Connecticut. The last Ungeheuer story to be published, The Effect of the Thorns of Country Flowers, was sent out two days after the funeral. He never published again during his life, though he continued to write regularly.
Inge died in her sleep on the 3rd of April, 1974. Within two years Ungeheuer had lost his two closest friends. Compounding this loss, Ungeheuer was questioned by the police with possible complicity in Inge's death. Ungeheuer disappeared for close to two years.