Unlock a simple lock with a lockpick.
In the same hallway as the second locked drawer in the castle is a lockpick, just find it and open the lock for the achievement. This happens shortly after defeating the first daughter. (Which is immediately after the castle demo segment, if you played it.) Alternatively, if you pre-ordered, you can just claim a free lockpick from the Duke in the castle, and unlock the first one you find.
Chloe ✅
