German plan for the invasion of the United Kingdom
... that a German plan for the invasion of the United Kingdom became part of the plot for a best-selling novel?
... that a <b id="mwBCs"><a href="./Imperial_German_plans_for_the_invasion_of_the_United_Kingdom" id="mwBCw" rel="mw:WikiLink" title="Imperial German plans for the invasion of the United Kingdom">German plan for the invasion of the United Kingdom</a></b> became part of the plot for <a href="./The_Riddle_of_the_Sands" id="mwBC0" rel="mw:WikiLink" title="The Riddle of the Sands">a best-selling novel</a>?