The adventure of the mazarin stone

Watson arrives at 221B Baker Street to find Holmes in bed at seven in the evening while Billy the page explains that Holmes has been hot on the trail of a missing jewel, a Crown diamond no less, worth about 100,000 pounds. This story was first written as a stage play by A.C. Doyle, and called The Crown Diamond. The story is told in the third person, not by Watson. First published in The Strand Magazine, October 1921.