When Daryl is looking for Lydia there is a "Silence the Whispers" message painted on her house door. This is not a typo (compared to the episode's title) but a reference to the comics. Alexandria residents painting "Silence The Whispers" graffiti on the walls is adapted from issue 152.
Production placed a real tree on top of Hilltop's barn. The tree was so large it had to be cut into three pieces in order to be transported to the set safely.
Having Michael Cudlitz back to direct his second episode isn't the only thing the cast and crew celebrated while filming. They also celebrated Josh McDermitt's birthday by surprising him with a cake.
Jerri Tubbs, who played Margo, also portrayed Diane Hopper in Season 1 of Stranger Things. Elle Graham appeared as her daughter on that show, but viewers may remember her as "Winnie" from last season where Judith gets taken.
When Magna, Luke and the others defending the wall decide they are being overwhelmed, they run to enter the gate on an adjacent section of the wall. For some reason, the walkers behave as if the living humans are not there at all, but rather continue to walk straight and head to a plain section of wall for some inexplicable reason.