 Hornung finished his work with the YMCA and returned to England probably in early 1919 , according to Rowland . He worked on a new novel but was hampered by poor health . His wife 's health was of even greater concern , so in February 1921 they took a holiday in the south of France to <unk> . He fell ill on the train with a <unk> that turned into influenza and pneumonia from which he died on 22 March 1921 , aged 54 . He was buried in Saint @-@ Jean @-@ de @-@ Luz , in the south of France , in a grave adjacent to that of <unk> . Doyle , returning from a <unk> lecture tour of Australia , received the news in Paris and travelled south in time for the funeral . 
