Guests gather at White Birches, the upper New York mansion of millionaire scion Justin Arnold. The weekend's festivities are cut short when the host inexplicably goes missing, presumed to be hiding or unwell somewhere within the grounds of the heavily protected, fortress-like estate. With the amateur sleuths unable to solve the mystery, they call in Detective Fleming Stone. What starts as a missing person thriller becomes a murder mystery in this clever locked-room puzzler from Carolyn Wells, author of The Clue.