Two bells have been dislodged from their place in the Bell Tower location of Hogwarts Legacy, incentivizing you to solve a fairly complex puzzle to get them back into place by using a clever combination of spells that levitate and move these objects. The first dislodged bell can be found to the right of the stairs, just leading to the main set of bells, as it represents a medium-sized part of the set that has fallen off its hinges. The second bell lies tucked under the second flight of stairs beyond that point and will thankfully be the easier of the two for you to maneuver due to its small size.
