The Black Mate
in The London Magazine (London, UK) Vol. 20 (Apr 1908): 
pp.120–240
- Collected as The Black Mate in Tales of Hearsay (1925)
- Subsequently serialized as L'Officier Noir in La Revue de Paris (Paris, France) (May 15, 1933)
View in Internet Archive BookReader (experimental). 
pp. 121-35.
Illustrated by A. Mason.