McCaleb

At the beginning of the story, McCaleb isn't enthusiastic about working on the case. He accepts the work only because he feels he owes something to Gloria's family as he ended up having her heart. He is just doing a favour. Then he studies the case and his passion for investigation strengthen his motivation to find the murderer. He falls right back into his old habits. Soon he has the intuition there is more to it than what it looks like. The more evidence he gets, the more thrilled he is. He forgets about the time, about his health.
His day to day routine is pretty much based on a search for details, which can seem long and unuseful, until he starts gathering pieces and rebuilding the murder.

When he finds out who the the murderer is, at first, McCaleb doesn't know how to deal with it. "I can't live with this", he says. He doubts he will ever find Noone. To him, it is all the more harder, than he was linked to the murderer. Actually McCaleb was the main reason the murderer killed the 3 people he investigated for days and nights. Hard pill to swallow... There is a thin line between Crimmins killing Gloria and him killing her. No wonder he feels like Gloria's dead because of him.

His talk with Graciela at that point helped him overcome the situation. Suddenly after having talked with her, he feels more confident he may find Crimmins.