"Survivor: Second Chance" can not decide how many tribes it wants. It was back to just Bayon and Ta Keo in episode 6, just two weeks after the CBS series had introduced Angkor to make it a three tribe game. Now, one week later, it is the time for the castaways to drop their buffs once again. A sneak-peek video for episode 7 teases a merge for the 13 remaining players -- the biggest merge in the series' 31 seasons.

The teaser shows both tribes receiving their weekly tree mail. Bayon is told to wait at their beach for "visitors," while Ta Keo is given instructions on where to find their "new home." That can only mean one thing -- a merge! 

The news elicits a variety of reactions. At Bayon, Tasha is immediately nervous about if she will be able to get her alliance on the same page on the new tribe. Meanwhile, at Ta Keo, Andrew, whose own alliance was just dealt a major blow by Kass with Woo's blind side in episode 4, is welcoming the shake up. He wants to be back with his original allies in Bayon. 

"Let this twist be something beautiful -- a beautiful merge," he tells the cameras.

Ciera, however, is worried what Andrew might do post-merge after having been lied to at tribal council in episode 6. 

Watch the episode 7 sneak-peek video below:

The episode 7 merge will be the biggest yet in 31 seasons of "Survivor." The show has previously never merged with more than 12 players and merges featuring 8 to 10 players have become the series standard. The oversized tribe should make for some interesting strategy and, potentially, some heated drama. 

Who will ended on the bottom of the totem pole -- and, likely, voted out -- after the merge? Fans will have to wait to find out. "Survivor: Second Chance" airs Wednesdays at 8 p.m. EST on CBS. 

Watch the promo for episode 7 below: