The Baldur's Gate 3 Silent Library puzzle is a pretty simple one, though it might not appear that way at first. Just like the Thorm Mausoleum with its confusing murals, the Silent Library also poses you a riddle: What can silence the Nightsong? You'll need to find the answer to this question and whack the solution into the altar to get access to the Spear of Night—an important item for both Shadowheart and the Nightsong quest.
You can find the Silent Library on the lowest floor of the Gauntlet of Shar, along the corridors from the third Faith-Leap trial room. It might look like there's a barrier over the door, but it's just that big Librarian orb enemy in the centre of the room shh-ing everyone, which you should destroy right away if you want to remove silence and cast spells again. Otherwise, here's how to solve the Silent Library puzzle and find out what can silence the Nightsong.
