Supernatural - Time After Time

It starts right off with Sam & Dean chasing something.  Dean getting to him first and then dissappearing with him.  Where did Dean go?  Then we flashback to Sam & Dean in a hotel room.  They get a call from Sheriff Jody and she tells them of some strange murders in Canton, Ohio.  So they head there anf find out that mummified bodies have cropped up at times in the last 90 years.  And also a man in a black fedora has been present in all of them.  They find out who is is, Ethan Snyder and follow him to his house and then follow him to an alley, which takes up back to where the show started.  Where did Dean go?

He was transported back to 1944 and he tries chasing Ethan and he gets caught by police.  A detective named Eliot Ness interviews him and Dean figures out he's a hunter.  So he gets him out of jail and they work together and figure out they are dealing with, Chronos (The God of Time).

In the meantime, Sam & Jody are trying to figure out what happened to Dean and what they are chasing.  They also come to the same conclusion as Dean & Eliot.  So then they figure out how to summon Chronos but they need Dean to be there to bring him back.

Dean uses skills learned from Back to the Future and writes a note to Sam and leaves it where Sam can find it.  He does and so they have a date, 1944, where Dean is.  They talk to a woman that was involved with Ethan at the time and she tells them the exact date & time that Dean gets killed.  So they end up summoning Dean & Chronos and killing him.  But right before he dies he tells them that their future will be covered in thick black ooze.  So we think it has something to do with the Leviathans.