Treyarch seems to be teasing Call of Duty Warzone Zombies with in-game crossover references.
The most obvious suggestion that Warzone is getting some sort of Zombies crossover is in the Verdansk Hospital map, where players have discovered something that wasn't there before: a janky trial machine from the Black Ops Cold War Zombies mode. You can't interact with the machine, save for a highly suggestive text pop-up that reads "ZAI/ACTIVATE_ZOMBIES." As Eurogamer notes, the same trial machine can be used in Black Ops Cold War Zombies to earn rewards by completing various challenges.
Soooooo.... There's a Cold War Zombies Trial Machine in Hospital On Warzone...🤔🤔🤔🤔🤔 pic.twitter.com/CUw7ZlkAhQFebruary 11, 2021
It isn't clear if this was an intentional tease from Infinity Ward or an accidental preview of what's to come. As you can see in the above tweet, the machine found in Warzone has some unfinished textures and the pop-up text looks like it could be a bit of leaked script, but this could just be Infinity Ward's way of drumming up intrigue. Either way, it sure does seem like zombies are coming to Warzone in some way, which would fit with the overall merging of Black Ops Cold War and Warzone that's been going on since December.
Another cryptic addition to Warzone seems to hint at a broader Zombies theme going into season 2. As seen below, players are noticing some screen distortion and unusual Russian dialogue upon entering a certain room. Redditor Wolf-of-icewrack was kind enough to offer up their translation of the message:
"Dispatch, this is Russian ship Vodianoy, channel 1-2. Over.
"This is dispatch, requesting shipping permit to Verdansk. Over.
"Dispatch, cargo secured, all systems are fine. Get ready to go. Over."
Playing warzone went in the office next to headquarters 2nd floor and this weird pop up plays and Russian voices start playing.WHAT IS THIS! from r/Warzone
The voice in the video up top seems to be discussing a shipment of some sort being transported by the Russian ship Vodianoy, and players think the ship is being used to bring Nova gas to and from Rebirth island. Twitter user @KStidge captured this in-game image of the Vodianoy near the island to support the theory.
Confirmed 😉 pic.twitter.com/fyoVBQivpBFebruary 12, 2021
In Call of Duty: Black Ops, Nova 6 was a biochemical weapon originally developed at Rebirth Island by Nazi Germany during World War 2 to use against major capital cities including Washington DC and Moscow. The gas also appears in the original Black Ops Zombies mode, and there's even a zombie called the Nova 6 Bomber, which looks like it funneled radioactive gas straight through its gullet.
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