In late 1944, U-864 was dispatched from Germany under the command of Korvettenkapitän Ralf-Reimar Wolfram to take part in Operation Caesar. This mission called for the submarine to transport advanced technology, such as Me-262 jet fighter parts and V-2 missile guidance systems, to Japan for use against American forces. Also on board was 65 tons of mercury which was needed for the production of detonators. While passing through the Kiel Canal, U-864 grounded damaging its hull. To address this issue, Wolfram sailed north to the U-boat pens at Bergen, Norway. On January 12, 1945, while U-864 was undergoing repairs, the pens were attacked by British bombers further delaying the submarine's departure. With repairs complete, Wolfram finally sailed in early February. In Britain, code breakers at Bletchley Park were alerted to U-864's mission and location through Enigma radio intercepts. To prevent the German boat from completing its mission, the Admiralty diverted the fast attack submarine, HMS Venturer to search for U-864 in the area of Fedje, Norway. Commanded by rising star Lieutenant James Launders, HMS Venturer had recently departed its base at Lerwick.