"Lion" rejoined the Battlecruiser Fleet, again as Beatty's flagship, on 19July. On the evening of 18August the Grand Fleet put to sea in response to a message deciphered by Room 40 which indicated that the High Seas Fleet, less the II Squadron, would be leaving harbour that night. The German objective was to bombard Sunderland the following day, with extensive reconnaissance provided by airships and submarines. The Grand Fleet sailed with 29dreadnoughts and 6battlecruisers. Throughout the 19th, Jellicoe and Scheer received conflicting intelligence, with the result that having reached its rendezvous in the North Sea, the Grand Fleet steered north in the erroneous belief that it had entered a minefield before turning south again. Scheer steered south-eastward pursuing a lone British battle squadron reported by an airship, which was in fact the Harwich Force under Commodore Tyrwhitt. Having realised their mistake the Germans then turned for home. The only contact came in the evening when Tyrwhitt sighted the High Seas Fleet but was unable to achieve an advantageous attack position before dark, and broke off contact. Both the British and the German fleets returned home, the British having lost two cruisers to submarine attacks and the Germans having a dreadnought battleship damaged by a torpedo.