An Occult Detective on Occasion
Every day, in my profession, we have proof of the existence of forces for which we have, as yet, no explanation — or, at best, a very crude one. I have had case after case of premonition; case after case of dual and even multiple personality; case after case where apparitions played a vital part in the plot which was brought to me to investigate.
So says Robert W. Chambers’ Westrel Keen, a detective who specializes in locating those gone missing. In fact, the series featuring this character is titled The Tracer of Missing Persons (1906). As suggested above, Keen occasionally handles a case that involves the supernatural.
Two of the five stories in the Tracer series involve the occult. The first, “Solomon’s Seal,” is a love story involving a man and woman who’ve never met. The tale touches on astral projection and “ghost” photography, but its use of an encrypted message seems to be the real focus. The second supernatural story is “Samaris,” which is mostly about a man trying to retrieve a mummy he stole from the men who stole it from him. Perhaps to give the case a more romantic, happily-ever-after spin, Chambers tosses in a bit of mystical magic at the end. I’ll just say there’s at least one way around being accused of having stolen a mummy.

Less Occult Detection and More Mushy Mystery
In other words, in each case, Chambers is writing a romance-mystery with a dash of the supernatural, not supernatural fiction that has a detective character and a dash of romance. Westrel Keen is likely to disappoint some fans of the occult detective cross-genre because of this. The supernatural is neither unsettling nor menacing here. Instead, Keen taps into the cosmic powers of attraction rather than the cosmic powers of evil or justice.
Nonetheless, Keen is an interesting and distinctive character in 20th-century mystery. He became especially prominent in radio from the 1930s to the 1950s and even made it to a television series in the 1980s. I really don’t know for sure, but I have a hunch that none of these subsequent adventures in electronic media included ventures into the occult. Let me know if I’m wrong.
Perhaps the author himself is the greater draw for fans of supernatural fiction. Chambers’ The King in Yellow (1895) is considered a classic of early weird fiction and a possible influence on H.P. Lovecraft.