Raintree: Haunted

This is in the Harlequin Nocturne series. Gideon Raintree is a homicide detective that has special powers that his entire Raintree line has although some have slight different ones. Gideon can talk to the dead. He uses this gift to solve his cases. Hope is assigned as his new partner. The Raintrees are targeted by Ansara wizards who want their powers or have them dead. Gideon winds up having to protect Hope as she finds out his secret and is targeted by Ansara as well.