When someone wrongs us, getting revenge can feel like the only right move — the only way for us to balance the scales, to set the world right again. But the consequences can be disastrous, especially when payback becomes an all-consuming obsession.

On this encore episode, we talk with lawyer-turned-researcher James Kimmel about his book, “The Science of Revenge: Understanding the World’s Deadliest Addiction — and How to Overcome It.” We discuss the evolutionary roots of revenge, the neuroscience behind why it feels so good, and how Kimmel eventually traded vengeance for forgiveness. We also find out what caused a murder of crows to target an unsuspecting woman, and what was behind their years-long grudge.