Oh, I quite liked this! We've seen so many "new recruit" stories before, but I like how yours grounds the story in Mira's point of view so well and thoroughly at the start. It makes for some interesting observations of HQ, like the alphabet and cultural tics, that we often take for granted. Well done!

As for your question about the Wiki: the nice thing about Wikis is that we can change them throughout an agent's life to reflect changes. So I would give the department as DMS for now, and change the infobox once Mira gets transferred.

—doctorlit looks forward to finding out what Frodo Mira has got in her pocket

On Mira's new wiki page there's a moderately detailed history which explains her backstory.

So I'm creating an agent page for Mira, but I have a bit of a problem. I eventually want to put Mira into the Department for Implausible Crossovers, but she's currently training in Mary Sues.

It says on the agent template "Department" and I don't know which one to put: I don't want to put her in Mary Sues because that's not going to be her department once she's finished training, but I also don't want to put her in Implausible Crossovers because she's not in that department yet.

Which should I put? Or should I just leave it blank for now?