In this chapter, we learn that Dr. Coppelius is hiding under the bomb's latticework, and that this is where Lilia's "magic square" is hidden. In order to solve the puzzle, Lilia has to fill in all of the squares in the latticework with the numbers she has drawn on the picture of the angel. The only problem is that the numbers are from the top to the bottom, so she has to draw the squares from the bottom to the top. In other words, she needs to draw all the numbers on the top and then draw the ones on the bottom. The problem is solved, but Lilia still has a long way to go.