Thirteen clans (including the lapsed Skaikru). Thirteen space stations (including the destroyed Polaris).

The symmetry seems obvious, and that doesn't exactly bode well for the fate of the Sky People at the hands of Lexa's twelve loyal clans on The 100 Season 3 Episode 7. Destruction seems imminent.

"Thirteen" focuses on Lexa's attempts to maintain peace in the face of the most recent Pike-led attack on Semet's village, an attack that led to Octavia's capture by the Grounders after she attempted to intervene to prevent bloodshed.

According to the official synopsis, Clarke is also set to discover a "game-changing truth" (about Polaris?) and we are going to be treated to a flashback to humanity's past. What's known about "Thirteen" is very vague, but either way, it promises to be a seminal episode.

Will Lexa survive her controversial decision not to attack Skaikru? Or will she be deposed? What the hell is going on with Titus and his motives? Will tragic Octavia meet her end in the crossfire between the two groups of people she has tried (and failed) to fit in among?

1. Commander on the Throne - The 100 Season 3 Episode 7

Lexa confers with Titus. These two have been at odds recently -- are they on the same page now?

2. Clansmen Congregating - The 100 Season 3 Episode 7

Various members of the thirteen clans gather around Lexa on her throne, likely to hear the discussion of the fate of Octavia (now Semet's prisoner). Clarke lingers to the side and Titus hovers near Lexa.

3. Bringing The Prisoner to Heda - The 100 Season 3 Episode 7

Semet presents a bound and gagged Octavia to Lexa, explaining the situation that led to Octavia's capture (the Sky People attack on his village).

4. Prisoner Octavia - The 100 Season 3 Episode 7

Poor Octavia. She was just trying to do the right thing by everyone -- warning the Grounders of the impending attack and warning Skaikru of the Grounders' counterattack -- and instead she is now an enemy of all.