Burn Bright by Patricia Briggs is an Alpha and Omega story in the same world as the Mercy Thompson stories. The events in this book take place after Silence Fallen and the book features Anna and Charles.
Dead Heat is the newest fantasy novel by Patricia Briggs. After a three-year wait, we get to return to the Alpha and Omega series (part of the Mercy Thompson world, a world with werewolves, fae, and vampires). The Alpha and Omega series features werewolves Charles and Anna.