Lost Property Trophy in Batman: Arkham City
No crimefighter should be without this
How to unlock Lost Property
Story related. If you want more info, continue reading. Otherwise, know that this will unlock through the natural progression of the story.
At the end of the first Robin section, you’ll find a piece of Batman’s equipment that he should have on him. There will be a group of about eight thugs around him. Once you knock them all out, the scene shifts to Batman and the trophy will unlock shortly after.