Kathleen Kavanagh, an Australian journalist, receives a letter from an Irish legal firm informing her that Fionnbharr Kavanagh, a distant great-uncle, has bequeathed his vast fortune and estate to her. However, there are conditions she has to meet before she can claim the inheritance. This news leaves Kathleen puzzled, since Fionnbharr has children, grandchildren and great-grandchildren of his own.

The history of Kathleen's family is a bloody one. In 1865, Kathleen's great-grandfather, Cormac Padraig Kavanagh, brutally murdered his wife along with her lover. Aggie Muldoon,...