in august 1921 she traveled to moscow with franz jung. the previous year he had visited lenin, arriving in may 1920 with party comrade jan appel. travel between two states in revolutionary turmoil was not without its challenges. in the absence of regular rail links, a hamburg-based communist called hermann knüfken was able to smuggle the men onto a steam boat called "senator schröder": once on board they persuaded the captain to alter course, and were thereby delivered to murmansk. his journey being illegal, in order to return home he traveled under a false name. back in germany, jung's political activity earned him several months in prison during the early part of 1921. he had already received soviet citizenship in june 1920 during his visit at that time, and franz jung would never lose his compelling enthusiasm for soviet russia. jung was banned from overseas travel, but nevertheless franz and cläre managed to cross into denmark at the end of august 1921, and then obtained a passage to the soviet union on a freight steamer called "flora": the two of them now settled in moscow. cläre obtained work as a secretary in the moscow office of the comintern central committee. after this she helped with reconstruction within the framework of workers international relief, and was involved in setting up orphanages in perm and jekaterinburg. she later worked, along with franz jung, on the rebuilding of the "ressora" metalwork plant in petrograd which, by the time circumstances had persuaded them to leave the country in november 1923, was back to producing steel oil barrels and ship building components.