Vin Gets Her Earring Back
Getting Vin's earring back to her proved a logistical problem here, perhaps one of the biggest puzzles in the entire book for me. If I pulled the earring, then Ruin couldn't talk to her, and I couldn't include the scenes of her and Ruin in jail. I felt they were very important—both to make good use of Vin's time while imprisoned, and to get across useful information about the nature of Ruin—his goals, his motivations.
And so, I needed to have Yomen give the earring back. But why? Why would he give a piece of metal to an Allomancer? Vin's reasoning in this chapter is the best I could come up with. Yes, Yomen has atium, ready to burn it. He is, indeed, trying to spring any traps Vin has ready. In fact, once he had her taken away, he followed a distance behind and waited by her cell for the rest of the day, expecting her to try something. When she didn't, he was rather confused.
The earring also presented a problem in that in the original drafts of book one, silver was an Allomantic metal. I later changed silver to tin and played with what the metals did. However, I didn't have the specifics of Hemalurgy down. And so, when I got this book, I worried that her earring would be the wrong metal. Hence the silver plating explanation, as I worried that I'd forgotten or missed some instances in book one where I mentioned the earring being silver. (I tried to cut all references to its actual metal, so that I would be open to build Hemalurgy as I saw fit.)
Notice that Ruin's voice doesn't come to her until after she puts the earring back in. As she points out later, his telling her to kill isn't as specific as she's interpreting it. He's just sending her a general feeling that she should kill and destroy; his attention is elsewhere at the moment, watching what Spook is doing.