Root ofall evil

This book is part of a series with the main character being Andrew Basnett, a retired professor of botany. Once again he accepts an invitation to stay with an aged cousin named Felicity in her Berkshire home over Easter. He discovers the reappearance of a former house keeper in Fecility's vicinity that creates a mystery which intrigues him, even though it is dismissed by her relatives when they arrive fr a family party. In any case, events at the party soon give them other things to think about, as they do Basnett, who now finds himself investigating a murder with all too many suspects and one motive: MONEY