"Save Leon" is a mission objective in Sequence 13 / Memory 02: The Book Thief
Walkthrough[edit]
There are 2 Raiders in the room with you. Take them out with careful attacks and some well timed parries. Once you have, head over to Leon in the cell. Talk with him and things don't seem to go so well. After a few words, the local leader will come in and attack Arno Dorian.
Most big Raider Groups will have a leader. If you kill this person, the rest will run off scared. Of course, you can also take out the others as well as they flee. Just head back to Leon when you are done. Talk with him once more.
This time he will realize the Arno is a person and not a ghost. He will tell you that they both need to hide. Open the door of the cell.