Scott, Allison, and Stiles hear stories from two unlikely sources. 

Peter tells Stiles about Derek being in love while he was a teenager.

Gerard talks to Allison and Scott about Deucalion.

Dr. Deaton and his sister Morrell are emissaries. 

Deaton and Morell can shift back and forth, keeping them connected to humanity.

Peter asked Ennis to turn Paige so she could be with Derek forever and they would be in good with Talia. 

Deucalion and his pack wanted to meet with Gerard but Gerard ambushed them.

It's because of Gerard that Deucalion cannot see.

Derek's hardened hard is explained.