The Christmas Wall is the ninth episode of Season 6. It aired on December 10, 2014.
Feeling unappreciated, Frankie decides on minimalist Christmas decorations this year. Meanwhile, thinking of Sue's allergies, Mike tries to purchase an artificial tree, but doesn't get what he paid for. Axl revives Boss Co. for the holidays, but when he and Sean argue about Rudolph the Red-Nosed Reindeer, Sean, Axl and Darrin's friendship is at stake. Brick attempts to write a Heck family Christmas letter detailing their past year, after seeing the same kind of letter in a card from a family the Hecks hardly know.