First i belive the order of the maos are

Verttuct
NDU
SNN
DR

But i belive that BOTH Verttuct and Der Reise were compiting for funding in creating zombies and DG-2 and SNN was just the Japanise try at creating zombies. The reason why NDU does not have easter egg's in my opinioin is because it's just a normal bunker yet Verttuct is an asylum filled with made scintest and my guess the insane and shellshocked troops.So the storyline start's with 4 Marines sent into rusian held terrotory under oparatin paperclip (to find and capture german scintist and bring them the the US) they go into the sanituriom to take a break when they hear voices and leave there weapons outside when the power goes out causing the door's to get separate them. the four some how make it out alive only to crash land at NDU on the way to get debrifed in the state's. The 4 marines fight untill Dempsy is the only one left and manage's to escape the same way it got free from the Japanese. Under Oparation Paperclip The US captures Dr. Rictofen and They find Nikiola in a drunken stuper within american territory. Takeo is captured on one of the japanise island's while he was practicing with his katana. Under Takeo's guide they go to SNN which is a secret reseach lab that they intercepted a distrese call from with what both Doc and Dempsy have already delt with and send Takeo and Nikola along because ther dispenible. they manage to survive semmingless endless wave's of zombie's and hellhound's when an american patrol group stumble onto the lab and rescue's them. they are then flown to a secret resarch facility in the US possibly area 51 were german scintist recreated the telaporter to send them to Der Reise. The plan was to send The 4 men in and then send support but when the got to the mainframe the power cut out not allowing anymore supplies and men through. And this is where we leave off waiting for MP4.