An encrypted build of Call of Duty 2021 may have briefly appeared on Battle.net under the name Slipstream, according to the operator of a Blizzard tracking website.
BlizzTrack is an independent site that monitors Battle.net for the uploading of new assets and builds. Helba, the owner and operator, tweeted Tuesday that they'd discovered logos for something called Slipstream in the vicinity of Call of Duty 2021 assets. The logo itself calls World War 2 to mind, drawing on strong rumors that Call of Duty 2021 will be set in that era.
The name Slipstream may be a reference to a 2008 radio drama of the same name focused on World War 2 (H/T Charlie Intel).
Slipstream, which appears to be referred to internally as "Fore," sported an executable called COD2021.exe, further supporting the theory the game was in fact the next Call of Duty in an early stage. Previous reports indicated Call of Duty 2021 would be titled Vanguard.
Fore was listed as having three different builds. One was simply named Fore, a second was named Fore (Dev), and a third was named Fore (Closed Internal Alpha). The closed internal alpha required a decryption key to access.
Helba also found evidence indicating Call of Duty 2021 would run a public alpha ahead of release.
For now, Helba is the only leaker claiming to see these files. Activision has yet to reveal Call of Duty 2021, whatever its name may be, but has previously confirmed Sledgehammer is leading development on the game.