The tree house was on the top of the palm tree. They were in the middle of the desert.
Jack and Annie looked out the window and found that the cat was at the base of tree. And they saw the parade toward to the pyramid. It was the same as in the picture of Egypt book. Jack read the caption of the picture. What they saw was the funeral of royal person.
Annie thought there must be mummies in the pyramid and knew Jack loved mummies. They wanted to see it and took off.
But the closer they got to the pyramid, the harder it was to see parade. They thought it was mirage or ghost.
At that time, they found the black cat. The black cat was staring at them. And slid the corner of the pyramid. Jack and Annie followed the black cat.