As Time Goes By
Supernatural Season 8 Episode 12 (01/30/13)
On this episode of Supernatural…
Henry Winchester, Sam and Dean's grandfather, travels forward in time looking for John Winchester to help him stop the demon, Abbadon, and protect a golden box.
Instead, Henry ends up in 2013 and he, Sam, and Dean try and figure out what the box is for.
The brothers learn that Henry was a part of a secret society of information collectors, where as the hunters would do all the work.
Sam learns that the box is a key to all the information collected on supernatural.
Abbadon, potentially one of the last of Lucifer's Knights of Hell, can't be killed with just a knife. They use a devil's trap on a bullet to keep her stuck, while burying her under concrete so she can't escape.
Unfortunately, Henry is killed in the process.
Sam and Dean learn that John's father never ditched him, but rather helped save Sam and Dean.
The brothers question whether the location for the key still exists.