The hole is right underneath Sabre's collage. Sabre’s collage is mostly filled with pictures of her sitting or sleeping on Raven’s feet, from his perspective. She’s grinning in a lot of them, showing fangs. One of the pictures moves, and it depicts a short scene of her handing Raven a dagger. Another shows him falling over onto the floor as he fails to carry her piggyback-style, and she sits on him.

The hole in the wall is actually more like an ensconced slot underneath Sabre’s portrait. It’s thin, and only about an inch and a half lengthwise. It looks like something could fit inside.

Sabre's poem.