At the turn of 1944 and 1945, Jewish underground activists wrote a number of letters. This was the last, no yet dispatched mail to London. During the Warsaw Uprising most of the ready material perished, thus this mail package was rather meagre when compared to the previous one of 120 pages. Another unusual aspect was the list of signatories, including some from right-wing Jewish parties, hitherto less known. as the Red Army was approaching, many Jewish underground activists began to ponder "what next?" It became evident that the obvious partners would now be communists and the Lublin "government". The correspondence reveals that the main link between the Jewish underground and the Polish government-in-exile was the funds channelled home by international Jewish organisations via the London government. Unlike other sources, these materials do not reveal a certain distance towards the London government, or the Polish underground as a whole. Certain issues such as those to do with Jewish conspirators in the Warsaw Uprising were described so as not to irritate the Poles. The presented mail contains a number of extremely important data on camps where the Jews were detained before and after the Warsaw Uprising, which demonstrates aid offered to the Jews by the Jewish National Committee (ŻKN), the Bund and the Council to Aid the Jews (RPŻ). Finally, it gives a synthetic description of Jewish underground activists and the Jewish population during the Warsaw Uprising.