As a matter of fact, von Feldoffer was thinking furiously. He had been given to understand by the German Admiralty that instructions would be issued to U-boat commanders concerned that the _Koning der Zee_ was not to be molested on the day arranged for the spy to cross the North Sea. On the strength of this assurance von Feldoffer started for England; but, although the U-boats carried out instructions, the floating mines, once launched, did not conform to the mandate of the Berlin Admiralty.