Mr. X's fourth room in Hohhot is called the Book of Light, which seems quite different from other places. There are four tables to adjust the time at first, I hope so.

On the first clock, there is English corresponding to the English in the wooden book. Looking for a map. After finding the graph, find the graph on the knob of the corresponding clock. Find the corresponding time point. The clock is on. Open the metal box under the table and take out a five-pointed star with two black pattern areas: one is long and the other is short. Stick the five-pointed star on the table and adjust the black area of the five-pointed star to coincide with the pointer. Open the second light box and take out a six-pointed star with the date on it. Find one in the room. There is also a date on the cross, and each date corresponds to a constellation. Look at the position of the constellation on the constellation disk and adjust the time of the third clock. The third clock was lit and the box was opened to get another cross. The button was pressed, but the secret door didn't open ... After a rest, I was too tired to continue.