3. Watch Dogs
Much has been said about the possibility that Black Flag and upcoming Ubisoft title Watch Dogs are linked. There are actually a number of references to the two universes being linked - from the Chicago setting through to the inherent link of hacking between the two games, but there is one definite reference that draws the two titles together. During the modern day Abstergo sequences, once you've gained the ability to snoop on co-worker emails (and gotten over the fact that collecting the post-it notes doesn't really lead to an awful lot) you'll find reference in one mail exchange that alludes to Blume, the corporation (in Chicago) that runs ctOS, or in other words, the security system that will be seen in Watch Dogs...
So what is ctOS? - CONFIDENTIAL: "Privacy is security." - INTEGRAL: "How did we ever do business without it?" - ACCESSIBLE: "The touch of a button!" - AVAILABLE: "We're everywhere... all the time." - STABLE: "It just WORKS." Put simply, ctOS is the most stable and user-friendly software security-controller ever devised. Can ABSTERGO afford to pass up perfection?
The exchange can be seen on the terminal directly to the right and behind of your own cubicle.