After starting this quest via reading the Dusty Scroll (abandoned library, access with the Old Well) and then talking to the ghost, the next objective will be "find a way to communicate".
The next quest marker is located just a couple steps behind and there should be a container. However, "should be" doesn't always mean "will be" in this case.
Exiting and reentering the area solved this issue for me. However, you may need to talk to the nearby librarian ghost to be able to exit (it will also advance you on a quest, which granted you access to this area).