Bruce Wayne may no longer be Batman, but his legacy lives on. When an assassin begins targeting all of Batman???s past partners, the former Robins must join forces to untangle a mystery that stretches back to the early days of the Dark Knight???s career. Years ago, Batman encountered a human trafficker known as Mother. Then-Robin Dick Grayson knew nothing of it at the time, but the case was much more complex than he could have ever imagined. Now, without Bruce to guide them, a grown-up Grayson and his allies must rely on the help of the silent, mysterious Cassandra Cain to pick up the trail and stop Mother???s deadly plans.