«Nick Carter at Headquarters» by John R. Coryell

Nick Carter at Headquarters is a detective story featuring the famous detective Nick Carter first published in 1897, written by John R. Coryell.
Nick Carter is a fictional character who began as a pulp fiction private detective in 1886 and has appeared in a variety of formats over more than a century. The Nick Carter name was treated as a pseudonym, and many of the volumes were written in first person. Nick Carter would go on to become one of the most popular heroes of the 19th and 20th centuries.