From the introduction:
Set in 1925… this scenario takes the investigators to the Great Lakes area of the United States—specifically to Grand Traverse Bay, at the northern end of the east shore of Lake Michigan. While playable in a single session, Insanitarium may take up to two sessions to fully play out.
A cluster of unexpected pregnancies, including alleged “virgin” ones, has caught the eye of Elijah Cleaver, chief editor and publisher of Strange But True! The investigators are charged by Cleaver with looking into the circumstances around the phenomenon.