Cordially Invited to Meet Death

Wolfe is hired by a society party planner to find out who is writing poison pen letters about her and sending them to her clients and potential clients. Since it appears that the letters are coming from a member of the party planner’s household, Archie is sent up to her Riverdale mansion to investigate. The client dies a few days into the investigation. Was it an accident or murder? Is there a connection between the death and the letters? If it was murder how was it done?