Rating: M (NC-17). Strong mentions of sex, suicide, and other angst in a similar vein.
Characters/Pairings: Jack/Ianto, Gwen/Rhys, Martha, Rhiannon, others may crop up as well.
Spoilers: Set after Exit Wounds
Summary: After 2,000 years buried beneath Cardiff, Jack's mind is crumbling. Ianto will do anything to avoid losing him again – but how do you fix a broken man?
A/N: This was originally a one-shot of the same name for my "What Cannot Be Expressed" Series. I was encouraged by several people to feel that this was a subject that hasn't received enough coverage, and that it would be better suited as a series. It's named after a song called "Kryptonite" by 3 Doors Down.