That his grief had made the orca wildly unpredictable and I felt an obligation to protect...

Rachel: So, Nolan's effort to spare his crew had failed, both the town and the orca had seen to that. I'd insisted on leaving South Harbor with them. I told myself that somehow I was responsible for Nolan's state of mind that I had filled his head with romantic notions about a whale capable not only of profound grief, which I believed but also of calculated and vindictive actions which I found hard to believe despite all that happened. Maybe I hope the voyage would show me another way to interpret the animal. It seemed a peculiar kind of human perversity to assume, but because the whale had an intelligence close to ours it would also have our most primitive and ugly emotion: vengeance. At this point I was sure of one thing: that his grief had made the orca wildly unpredictable and I felt an obligation to protect both it and Nolan, from the consequences of that insanity. Nolan however seemed sure of what was going to happen next, and that frightened me more than anything else. He set our course for the exact locale where he had killed the whale's mate. Nolan was certain that the creature would want to catch up with him there