I said we're CLOSED! is an achievement in the Call of Duty: Black Ops III Zombies remake of Nacht der Untoten. It requires the player to not allow any zombies to get through the windows during the first three rounds.
A simple way to do this achievement is to have four players each guard a window in the spawn room with either an RK5 or Sheiva, while someone would have to double up on the fifth window. The use of the Dead of Nuclear Winter and Round Robbin' GobbleGums can also make this achievement easy as well. After reaching the beginning of round four, the achievement will unlock if no zombie steps foot in the building.