Karen finally made it through the goblin city. She had expected an all-out frontal assault, but was quite shocked when the only opposition she met was a cat and a particularly defensive chicken. But when she made it to the entry of the castle, she understood why.

Sitting in front of the door was a massive sphinx, large enough that it blocked the entire doorway. It glared at Karen, analyzing her with a single glance, and then it spoke.

"I am not the last challenge you will face here," it said. "But should you wish to proceed, you must solve my riddle."

Karen mentally prepared herself for this, ready for anything it might throw at her. The sphinx dropped its head down to her level. Its head was as tall as she was. Karen gulped.

"What comes at night without being called, and disappears in the morning without being stolen?"

Karen's mind raced with all sorts of things of the night. It might have been dreams, but no, it couldn't be. Some people sleep in the day, and plenty of people have daydreams. It could have been the moon, but everyone has seen the moon during the day. It's revolution around the earth wasn't constant in that sense, and it didn't always appear, such as on a new moon. No, there was only one right answer.

"Is it the stars?" she asked tentatively.

"You must be firm with your answer," the sphinx said. "Never wavering. I will not accept a question for an answer."

Karen planted her bare feet firmly on the ground. "It is the stars." The sphinx nodded and stepped aside for Karen to enter.