Lockpicking I lets you open London's locked chests, which hold money, materials and several crafting schematics and unique materials. It is a one-point buy after Sequence 1 and worth getting early.
Lockpicking I sits at position 5 of 19 in the Stealth tree. Unlocking Lockpicking I takes 1 skill point. You need to complete Sequence 1 before you can buy it. Jacob and Evie each have their own skill tree, so you buy Lockpicking I once for each twin.
Air Assassination
Drop onto a target from above and kill him in a high-profile strike.
Assassin Steps
Greatly reduces fall damage, silences your landings and makes your movement much quieter.
Chameleon
In Sneak Mode, Evie becomes invisible while standing still; only enemies very close by can spot her.
Double Assassination
Kill two nearby unaware enemies at the same time.