As Maclean was preparing for the return journey, an urgent signal arrived from Vivian Street stating that on 25 May there had been a large-scale airborne attack on Partisan HQ with gliders and parachute troops, that the Partisans had suffered heavy casualties and that Tito and the Allies' missions had managed to escape capture. Unbeknown to him, a meticulously planned and executed Operation Rösselsprung was underway. Tito had by now realised that he could no longer lead the Partisan movement while being constantly on the move. The decision was made to evacuate the HQ and the missions, first to Bari and then onto Vis. The flight was organised by the RAF and executed by a Russian crew.