'Rassendyll' was a British intelligence deception by Colonel Peter Fleming’s 'D' Division in Burma (?).

A copy of Charles Kingsley’s The Water Babies, containing concealed codes, intelligence information and schedules, was dropped to the 'Brass' party of three Karen operatives who had earlier been dropped near Rangoon and were known to have been captured by the Japanese in November 1942 and used in a Japanese deception effort. The British instructed the 'Brass' team to send the book to Tokyo where, it was hoped, the Japanese would attempt to create a fictional sub-source which the 'D' Division would then exploit.