"Crossed" is the first episode of Season 5 with all main characters in it.
In the scene right before the opening credits, a sign with bible verse locations can be seen inside the church. Each of the bible verses mentions the undead.
Glenn asks Tara what GREATM means (the first letter of each person in the group's first name), and she tells him "Us. Group name. Solidarity. Band of Brothers." Michael Cudlitz, who plays Abraham, was in the Band of Brothers (2001).
Originally the title for this episode was "Straight" but was changed for reasons unknown.