#OTD in 1907.
Gaston Leroux's pioneering locked room mystery, The Mystery of the Yellow Room (Le Mystère de la chambre jaune), begins to be serialized in L'Illustration, Paris.
The novel finds its continuation in the 1908 novel The Perfume of the Lady in Black, wherein a number of the characters familiar from this story reappear.
https://en.wikipedia.org/wiki/The_Mystery_of_the_Yellow_Room
The Mystery of the Yellow Room at PG:
https://gutenberg.org/ebooks/1685