Complex sentence: Meanwhile, MI5 have discovered a radio signal transmitted from Walmington-on-Sea towards Berlin, apparently the work of a spy, giving the Home Guard a chance to make a real difference in the war.
Split into simpler sentences: Meanwhile, MI5 have discovered a radio signal transmitted from Walmington-on-Sea towards Berlin, apparently the work of a spy. This gives Home Guard a chance to make a real presence in the war.