The Devil's Due

In the sixth book of the Devil Series, Cain and Emma are now married and have returned to a Katrina-ravaged New Orleans to await the birth of their third child. Cain’s wedding gift to Emma was peace of mind with the death of Juan Luis and his mother, but Anthony Curtis is still a threat who has disappeared as effectively as the Luis family once did. The Casey alliance with the Jatibon and Carlotti families is strong, but there are new and old enemies, as well as the ever-present FBI that are working to bring Cain down. 

All this weighs on Cain as she tries to come to terms with the addition to her family she never thought was possible. A daughter her father never knew about means a sister Cain now knows exists, and must now come to terms with.