Winter’s Moons by Lise MacTague

When Cassidy Nolan agreed to take over as the Alpha for Chicago’s North Side werewolf pack, she knew she was in for a challenge. Four months later, and she’s wondering how things deteriorated so far so quickly. Her sister—the Hunter of Chicago, a genetically-engineered werewolf/vampire/demon slayer—has disappeared, and wolves from her pack are vanishing without a trace. Complicating matters is the lone wolf in town whose motivations Cassidy isn’t sure she trusts.