Dead Man’s Gift – Zelda Popkin (1941)

Six heirs to a massive fortune gather in a small Pennsylvania town for a reading of the will and to learn their stake.  The strange thing is, none of them know the benefactor, despite all sharing his last name.  And, as it turns out, this is one of those wills where the money gets evenly divided among the heirs who are still living…

Not that atypical of a set up for a Golden Age mystery, but Zelda Popkin throws in the curve ball of a town beset by a rising flood.  The heirs soon find themselves trapped in a mansion quickly filling up with water, without any power or a means to contact rescuers.  Oh yeah – an oil tank has released a spill, and a blazing slick is headed their way…