Different as “Lost” and “Supernatural” may seem to most, there are actually a number of thematic parallels — as our good friend Mo Ryan, aka The Watcher, points out in this post.

There’s really no excuse for any genre fan not to have seen at least one episode of this show.  Honestly, folks, it’s on TNT every weekday.  In fact, the only thing that gets me to the gym in the morning is knowing I can switch on those “Supernatural” repeats while I do my cardio.  Gotta prepare for the coming zombie apocalypse, right?  Next goal: Limber up!

But this is not a discussion about “The End.” Rather, it is a short take on what to expect from this week’s episode “The Song Remains the Same,” previously titled “Back to the Future II.”

The new episode (airing Thursday at 9 ET/PT) marks the return of Anna Milton (Julie McNiven), the fallen angel who recovered her grace with the Winchesters’ help. As part of the adventure, Dean and Anna had a “last night on Earth” romantic encounter that was scored to a rock ballad so awful it could peel paint.  Anyway, Anna evaded capture for several episodes but sadly, she was being hauled heavenward last time we saw her.

This time,  according to the official episode summary,  Anna jumps through time to Sam and Dean’s past. Her purpose: to hunt down the young versions of the boys’ parents, John Winchester (Matt Cohen) and his wife Mary (Amy Gumenick), and make sure Sam never comes into existence.  Let’s see, time travel and seeking to change the past in order to alter the present.  Hmm — are we sure this isn’t “Lost”?

Click on the photo at left to see a tasty video clip from tonight’s episode, or go here.

We have plenty of photos from “The Song Remains the Same” available here,  and check IMDb’s homepage on Friday for the recap.