Joanna Sloan.
Secretary to psychiatrist Dr. Myron Braam.
When Miss Sloan suspects that her employer is up to no good, she calls Maxwell Smart, who she knows is a secret agent because she lives in his apartment building and once saw him talking into his shoe.
Unfortunately, before she can finish, the telephone booth she is in fills with water and she drowns.
It is later falsely reported that she drowned in a river.
Portrayed by Merry Anders [Episode #20: "All in the Mind"].