While Pujol downplayed the extent of V-1 damage, trouble came from "Ostro", an agent in Lisbon who pretended to have agents reporting from London. He told the Germans that London had been devastated and had been mostly evacuated as a result of enormous casualties. The Germans could not perform aerial reconnaissance of London, and believed his damage reports in preference to Pujol's. They thought that the Allies would make every effort to destroy the V-1 launch sites in France. They also accepted "Ostro"s impact reports. Due to Ultra, however, the Allies read his messages and adjusted for them.