Anything Goes — Jill Churchill

They Have Inherited a Lovely Upstate Mansion...

The crash of 1929 has ended the party for high-living New Yorkers Lily Brewster and her brother Robert and takes them from the upper echelons of the idle rich and deposits them to the lowly depths of the disillusioned poor. However, rescue arrives in the form of their recently deceased great-uncle Horatio who bequeaths to them Grace and Favor "Cottage" which is really a great sprawling mansion. And there's a fortune to go with it, but only if they reside there for ten years.

And an Inconvenient Corpse

With no other alternative, the spirited Manhattanites move to a quiet and quaint Hudson River community and try to fit in. But they soon find out that great-uncle Horatio didn't die peacefully. He was murdered while on an elaborate sailing party on the Hudson River aboard his yacht -- and Lily and Robert are suspects. But when another corpse appears in the kitchen of the mansion, the siblings are determined to clear themselves. Without a clue how to begin, Lily and Robert start snooping, unaware that their savvy sleuthing could make them the killer's next targets.