The Trail of Cthulhu (Derleth)

The Trail of Cthulhu is a novelette written by August Derleth.  It was first published in Weird Tales, March 1944.  It was reprinted in the 1962 collection The Trail of Cthulhu and the 1997 collection The Cthulhu Mythos.  It was reprinted again in the 1998 collection In Lovecraft's Shadow: The Cthulhu Mythos Stories of August Derleth.