The final face off between the Mountain Men and the Grounder/Ark alliance has been a long time coming. 

Our heroes have overcome their differences... and that pesky acid fog problem. Now, at the start of The 100 Season 2 Episode 15, they stand ready outside Mount Weather, with only a set of doors between them and the evil Mountain Men. 

This slideshow from "Blood Must Have Blood, Part I" gives us a look at what's to come as we mentally prepare ourselves for part one of the season finale. 

The 100 Photos from "Blood Must Have Blood, Part I"

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With only two episodes left in the season, we may not know what is going to happen, but we can assume it is going to simultaneously excite us and break our hearts a little bit – like only the best TV tends to do.

After all, this is a war and no one is safe. If the title "Blood Must Have Blood" is any indication, there will certainly be some casualties ahead.

From the looks of it, Lincoln is playing a central role in the battle, seen front and center next to Clarke. Last time he was at Mount Weather, he put Bellamy in a pretty harrowing position for a hit of Reaper drug, so it should be interesting to see how he reacts this time around. 

The Grounders are attempting to gain access to the mountain, but it looks like it is easier said than done. Maybe Clarke was right to be concerned about their plan for the doors in The 100 Season 2 Episode 14?

Inside Mountain Weather, Bellamy has reunited with Jasper and Monty (and it would feel so good, but it looks like they have stumbled into some trouble). 

Bellamy does manage to keep his promise to Echo, returning to free her and the other Grounder prisoners from the cages.

Now, with the Grounder army unleashed inside, as well as outside, the Mountain Men don't stand a chance.

Or do they?  I can't take the suspense. Is it Wednesday yet?!

If you are still catching up, watch The 100 online at TV Fanatic and get ready for the not-to-be-missed season finale.