K. and Inge finally left Berlin in 1933, as Hitler's Brownshirts took over the city. They moved to Lisbon, Portugal where Inge had some family. Exile in Portugal separated Ungeheuer from his friends in the publishing world and even though he continues writing constantly, he ceased 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 Ungeheuer 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 literary magazine called The 10 cent Gutenberg. 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 and support provided by Marsteen, Die Kunst des Mittlealters [The Art of the Middle Ages] was released in 1967. Ungeheuer fell in love the New York City of the 1960s and often compared it to the Berlin of his youth.
Unfortunately Jacob Marsteen died of a drug overdose in 1972 at a party in Connecticut. The last Ungeheuer story to be published, The Effect of the Thorns of Country Flowers, was printed just 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. To compound the tragedy Ungeheuer was questioned by the police several times with possible complicity in Inge's death until an eventual coroners report showed that Inge died of a stroke. Ungeheuer went into isolation for close to two years.