This excerpt focuses on a very important message that men are trying to decipher, in the way they achieve to figure out important an important detail (the 90000 family indicates important names) that leads them to finally get where they wanted to: the author of the message, Zimmermann.
We can infer that the men had intercepted that important message because of the shock and the excitement the men showed when they discovered that the message was sent by Zimmermann, and from that point on they eagerly started working on the message from the beginning.