Complete Assassin's Creed Chronicles: India in Plus Hard mode without being seen once.
You are able to kill your enemies and they can see dead bodies but you just cannot be seen.
Use eagle vision often as it will help out a lot on tougher levels.
If you think you made a mistake or are unsure just restart the checkpoint.
Better safe than sorry.
On sequence 10 the only advise i can give is at the end of the level where you got to avoid the enemies visions use eagle visions as much as needed. Take your time be patient and dont rush.
Videos should help out if you get stuck on some parts of the game.
I take no credit for these videos the credit goes to (360GameTV).
update: it has been confirmed that you don't need to go through a single playthrough. if you get seen in any of the sequence level and can't go back far enough for the checkpoint, don't panic. you can just simply restart on that level and continue and it will still count for the achievement.
credit goes to (Jacques Bauer)
thank you (Jacques Bauer) for confirming this.
Enjoy and happy hunting.
Memory sequence 1
Memory sequence 2
Memory sequence 3
Memory sequence 4
Memory sequence 5
Memory sequence 6
Memory sequence 7
Memory sequence 8
Memory sequence 9
Memory sequence 10
If you have any questions or concerns please feel free to comment.