The Adventure of the Red Circle - a Sherlock Holmes Short Story

Something strange is going on.

A landlady visits Holmes and Watson asking for help. A prospective tenant visited her recently, said he would take her vacant room at double the usual rate and took the unit, and then she has never seen the tenant again. She knows the tenant is in there, she can hear footsteps and the meals get eaten, but she is worried. Can our famous detective help?