Assassin's Creed Rogue is yet another addition to the franchise, but rather than being part of Unity, the game seems to be a continuation of AC IV.
You play as Assassin-turned Templar Shay Cormac, who for some reason decides to switch allegiances from the side of the Assassins to their bitter rivals. We're presuming that's why the final tagline is "question the creed".
The game promises to introduce some rival assassins who are doing their best to take you out, and you need to be on high-alert at all times to make sure that death doesn't arrive upon your from above or from somewhere hidden in the bushes, something that should shake up the single player gameplay a little bit.
Cormac, dodgy-accent aside, is on a mission to hunt down all the assassins he can and take them out, and equally they want him dead before he can spill the beans on all their inner-workings to their enemies, so in terms of a plot line, this newest addition to the franchise is setting up quite nicely.