Technische Hochschule Berlin. A search team soon rounded up Timofeev-Resovskij's colleague Nikolaus Riehl. In early July, Riehl was flown to Russia to head up a group at Plant No. 12 in Ehlektrostal’ (Электросталь) for the production of metallic uranium within the Soviet atomic bomb project. Other colleagues of Timofeev-Resovskij, namely Born, Catsch, and Zimmer, were also sent to Russia to work with Riehl. After the fall of Berlin, Timofeev-Resovskij was arrested by the Russians. However, Colonel General Zavenyagin recognized that Timofeev-Resovskij's experience in radiobiology and genetic effects of radiation would be useful to the Soviet atomic bomb project and ordered his release. Timofeev-Resovskij became director of the KWIH facility in Berlin-Buch and was visited by Zavenyagin, and also by Igor’ Vasil’evich Kurchatov, chief scientist of the Soviet atomic bomb project. However, after being denounced by a visiting scientist in an Academy of Sciences delegation from Moscow, Timofeev-Resovskij was secretly re-arrested on 14 September by an element of the NKVD different from that under Zavenyagin. Timofeev-Resovskij and Tsarapkin were sent back to Russia; both were incarcerated in the gulag – Timofeev-Resovskij received a ten-year sentence. On his way to the prison camp in Karaganda in northern Kazakhstan, one of the most terrible camps in the GULAG, Timofeev-Resovskij went through the Butyrskaya prison, the central transit prison in Moscow. It was there that he met Aleksandr Solzhenitsyn. Even in prison, Solzhenitsyn noted, Timofeev-Resovskij organized a scientific seminar. He made a presentation on the biophysical analysis of mutations. Himself he was strongly impressed by the talk of unknown priest about "shameless death". The harsh conditions of his transportation and incarceration in the labor camp contributed to a significant decline in Timofeev-Resovskij's health, including the degradation of his vision brought on by malnutrition. Frédéric Joliot-Curie, a Nobel Laureate in Chemistry and a leader in the French Resistance during the war, visited Moscow and pleaded with Lavrentij Beria, the head of the NKVD, that Timofeev-Resovskij should be found and given meaningful work. The argument did not fall on deaf ears, as Beria was also in charge of the Soviet atomic bomb project, and this was a top priority for Joseph Stalin. Eventually, Timofeev-Resovskij was found, treated for his ill health brought on by his incarceration in the GULAG, and was sent, in 1947, to work at Laboratory B in Sungul', which was a ShARAShKA. While he was still a prisoner, he headed up the biological