As soon as you enter the first flashback of episode 1 (the one that takes place inside of a plane) you get the chance to unlock your first achievment for the game. First of all you will need to zoom and focus in on Kates hands as she grabs the bottle of water. You are wanting to focus on the handcuffs. After a small and brief cutscene you will then need to "investigate" the following items.
Once you have done this the achievement will unlock.