"The Horror in the Museum" is a short story ghostwritten by H. P. Lovecraft for Somerville, MA writer Hazel Heald in October 1932. It is one of five stories Lovecraft revised for Heald. The story has been reprinted in several collections, such as The Horror in the Museum and Other Revisions. Heald had been introduced to Lovecraft by his Providence friend Muriel E. Eddy (see C. M. Eddy, Jr.).
The tale concerns the relationship between Stephen Jones and George Rogers, the owner of a private wax museum specialising in the grotesque. Initially cordial, it degenerates as Jones first mocks Rogers then comes to suspect that he is demented with his "wild tales and suggestions of rites and sacrifices to nameless elder gods". Jones takes up Rogers's standing offer to spend a night in the museum and is attacked by his host, who is in turn killed by the entity Rhan-Tegoth that he has been making sacrifices to, and ends up becoming part of the displays.