CAIN HIS BROTHER - VG
Perry, Anne - 6th in William Monk series
Struggling to rebuild his own identity, detective William Monk steps into the shoes of Angus Stonefield--missing and presumed murdered--to track down the truth. If Stonefield is indeed a murder victim, the likely culprit is his own brother, Caleb--Angus's identical twin in appearance, but his sinister opposite at heart.
the relationship between Monk and Hester is slowly building. Perry never disappoints, her books are always wonderful.