This thread isn't about Rudolph's future; can he be redeemed, will Harry forgive him or will a dark entity offer Rudolph real power, like one of the Blackened Denarius coins. (I like that last idea.) This post is an open question about Jim's writing, about what he was trying to do when he introduced Rudolph in Fool Moon and used him again in Grave Peril.
I just started rereading the series again and just finished Grave Peril. Now, I'm trying to remember if we see Rudolph again before Changes. Maybe his name was mentioned once; that he'd left Special Investigations to go to Internal Affairs, but other than that I think he pretty much disappears from the overall story.
I'm wondering if the character of Rudolph is similar to Waldo Butters. Perhaps Jim just needed a bumbling idiot and someone who couldn't believe what he was seeing when the Loup Garou was rampaging through S.I.'s HQ, but then decided to expand the character and make him a thorn in Harry's side.
In Grave Peril we find out that Rudolph ran away rather than face Kravos and his demon. So, by the third book Rudolph is a complete coward. In Fool Moon, Rudolph is in shock and he's panicky, but he isn't running away. Of course it helped that Carmichael told Rudolph to stay with Harry, but panicked as he was, at no time did it look like Rudolph would bolt and run.
Also in Grave Peril, Jim sneaks in a continuity error about Rudolph; which I don't think was an error at all, just another subtle indication we are watching events taking place across a multiverse. After describing Rudolph running away from Kravos, Harry says, "Before that, I'd escaped police custody while he (Rudolph) was supposed to be watching me. I'd had a darn good reason to escape, and it wasn't really fair of him to hold that against me, but hey. Whatever got him through the day. " But that was wrong. Rudolph wasn't at Harley MacFinn's mansion, or if he was we never saw him. More important, it was detective Carmichael who put Harry in a police car and left him by himself, which allowed Tera West to help Harry escape. (OK, this entire paragraph is a bit off topic, or maybe not. I just had never noticed that continuity error before.)
Then there's this other bit of odd dialog between Rudolph and Harry in Grave Peril, after the Nightmare had attacked Murphy. Rudolph's expression was serious, earnest. He'd never much liked me, anyway. ""You'd better not be a fake, Dresden," he said, quietly. "I'm not really sure what's going on here. But so help me God, if something happens to the lieutenant because of you ... "I mean it, Dresden. If you let Murphy get hurt, I'll kill you." What is that all about? Does Rudy have a crush on Murphy, is that why he cares what happens to her, or is this more multiverse shenanigan's? Maybe we are seeing a scene in one universe where there is a Rudolph who actually cares about the people he works with, someone who isn't a total jerk. I don't know.
To get back to my main point, am I forgetting something? Is Rudolph in any of the books or short stories that run between and include Summer Knight and Turn Coat? If not, is he mentioned in one of them? I wonder if there are any more clues that I am missing.
