This satisfied for a time his desire to visit the earth cities, but soon the monotony of his existence again made him restless and gave him another thought. At night the people slept and the cities would be quiet. He would visit them at night. So at the proper time Popopo transported himself in a jiffy to a great city, where he began wandering about the streets. Everyone was in bed. No wagons rattled along the pavements; no throngs of busy men shouted and halloaed. Even the policemen slumbered slyly and there happened to be no prowling thieves abroad. His nerves being soothed by the stillness, Popopo began to enjoy himself. He entered many of the houses and examined their rooms with much curiosity. Locks and bolts made no difference to a knook, and he saw as well in darkness as in daylight. After a time he strolled into the business portion of the city. Stores are unknown among the immortals, who have no need of money or of barter and exchange; so Popopo was greatly interested by the novel sight of so many collections of goods and merchandise. During his wanderings he entered a millinery shop, and was surprised to see within a large glass case a great number of women’s hats, each bearing in one position or another a stuffed bird. Indeed, some of the most elaborate hats had two or three birds upon them. Now knooks are the especial guardians of birds, and love them dearly. To see so many of his little friends shut up in a glass case annoyed and grieved Popopo, who had no idea they had purposely been placed upon the hats by the milliner. So he slid back one of the doors of the case, gave the little chirruping whistle of the knooks that all birds know well, and called: “Come, friends; the door is open—fly out!” Popopo did not know the birds were stuffed; but, stuffed or not, every bird is bound to obey a knook’s whistle and a knook’s call. So they left the hats, flew out of the case and began fluttering about the room. “Poor dears!” said the kind-hearted knook, “you long to be in the fields and forests again.” Then he opened the outer door for them and cried: “Off with you! Fly away, my beauties, and be happy again.” The astonished birds at once obeyed, and when they had soared away into the night air the knook closed the door and continued his wandering through the streets. By dawn he saw many interesting sights, but day broke before he had finished the city, and he resolved to come the next evening a few hours earlier. As soon as it was dark the following day he came again to the city and on passing the millinery shop noticed a light within. Entering he found two women, one of whom leaned her head upon the table and sobbed bitterly, while the other strove to comfort her. Of course Popopo was invisible to mortal eyes, so he stood by and listened to their conversation. “Cheer up, sister,” said one. “Even though your pretty birds have all been stolen the hats themselves remain.”