Okay, this one has been on my mind for a while, but all I can remember is some obscure plot points from near the end of the fic!!!

I remember that Kagome and Sesshomaru have already formed a "relationship", or at least feelings for each other, in the past, but after the Jewel is complete she somehow gets sent back to the present.

During the 500 year interval, Sesshomaru works tirelessly on developing a way for humans to have the same lifespan as a demon. His first attempt he tries on Rin, and while it does prolong her life, she continues to age like a regular human, and looks pretty old by the time Kagome's time period rolls around.

When Sesshomaru finally DOES perfect the potion/serum/what-have-you, he tricks everyone else into consuming it without their knowledge. By the time they realize what he has done, they are all furious with him, but he doesn't care because it means that Kagome will be able to have them all survive to her era. When the time rolls around, he finds her, and gives her the choice of taking the formula/potion/tonic/what-have-you... or maybe he tricks her too??? ARGH I CAN'T RECALL!!!

REALLy would like to re-read this one, anyone think they know it??

You are looking for a story by JustAnotherGirl... the first one was "Inexcusable Nature," which you can find here:

http://www.dokuga.com/spark/story/942/1

and the sequel, which you're describing, is called "An Inexcusable Death:"

www.dokuga.com/spark/story/1436/1

Both are rated PG-13 on 'Spark, but would most likely be M here.

ENJOY!

~~Wiccan~~

I think you might be looking for Inexcusable Nature and An Inexcusable Death by Just A Starving Writer. They are rated T on FF.N (where the links go), but might be rated M or MA on Dokuga.