Question About NBC's "Heroes"...?

I am currently on season 1 of "Heroes". I just watched the episode
"Unexpected" (Season 1 Episode 16). To help, it ends with Matt (the
mind-reading cop), some new computer-powered girl, and some guy name
Ted Sprague (the dude with fiery hands) abducting Claire's father and
her family. Now, I remember this Ted character being questioned by
Matt back when he was in FBI, but don't remember how it ended...
that's where you come in. I remember learning about Ted's past, but
not much... something about his wife or someone dying somehow that i
don't remember. In a recent episode he was standing over this person's
grave and all the grass around him in the cemetery started to burn.
What was this guy's past?

DO NOT GIVE ME ANY SPOILERS!!! IF I AM WRONG AND HIS PAST WASN'T YET
REVEALED, THEN DO NOT TELL ME!!! IF YOU ARE NOT SURE WHETHER OR NOT
YOUR ANSWER IS A SPOILER, THEN PLEASE DON'T SAY IT!!!

thank you. But seriously, NO SPOILERS!!!