Dr. Spike is the local doctor in Canterlot, he is also a scientist in the search of a new world, but he is also doing that for his father, who is at the dragon lands suffering from a mental disease; the doctor comes up with a solution that'll solve the problems of the ponies forever, unfortunately, his idea gets rejected and he is left heartbroken...

After that, some deaths start occurring in Canterlot, which is followed by the doctor's strange behavior and affection towards his work rather than his friends.

What will Spike do to stop these deaths? How is his work connected to the carnage on Canterlot? Will he stay in conditions for his upcoming wedding?

This story will contain some gore afterwards, be warned.
All the characters are older, including Rarity and some other characters that might appear, including Spike and Sweetie Belle.
If you couldn't already tell, there will be some Spikebelle moments in this story.
Sex tag for sexual themed situations and implied sex, there won't be anything explicit.
Rated Mature just to be sure.
Still need to work on my grammar, orthography and the pacing of my stories.
If you're asking, yes, this IS a Jekyll and Hyde crossover, there's no need to point it out in the comments.