User blog comment:Argorrath/Treyarch posts a message of zombies; possibly hinting to a DLC 4/@comment-50.46.177.41-20130801001343

heres what i think. one letter mentions the "Motherland" meaning Russia, another one mentions the emperor and Japan, Another one mentions "The Doctor" and Element" possibly referring to Richtofen and 115. and the last one is possibly referring to dempsey which in my opinion means that the final zombie map has something to do with them. that is what i believe anyway