Very interesting. I noticed that you have this as Completed. I hope not. You brought up some interesting questions, like what was the drug? And could it have something to do with Ritsuka's amnesia? But it's a good read no matter what.
Author's response
This fic is completed, but it is part of a fanfic100 challenge I am currently doing. Each of the other 99 fics will be in this 'verse, but will be stand-alones. The questions will be answered in later parts. Thank-you for reading, and I'm glad you liked it.