I'm looking for a fic that I'm pretty sure was mcshep. One of them, Rodney had a symbiote, probably Tok'ra. I'm a little fuzzy on the details but the one thing I remember was that Rodney put the symbiote in John's head for some reason and they both though that Rodney was dead. I think the story resolved with them sharing the symbiote back and forth between them. Any ideas?