All day long Mary Poppins had been in a hurry, and when she was in a hurry she was always cross.

      Everything Jane did was bad, everything Michael did was worse. She even snapped at the Twins.

      Jane and Michael kept out of her way as much as possible, for they knew that there were times when it was better not to be seen or heard by Mary Poppins.

      “I wish we were invisible,” said Michael, when Mary Poppins had told him that the very sight of him was more than any self-respecting person could be expected to stand.

      “We shall be,” said Jane, “if we go behind the sofa. We can count the money in our money-boxes, and she may be better after she’s had her supper.”

      So they did that.

      “Sixpence and four pennies – that’s tenpence, and a halfpenny and a threepenny-bit,” said Jane, counting up quickly.

      “Four pennies and three farthings and – and that’s all,” sighed Michael, putting his money in a little heap.

      “That’ll do nicely for the poor-box,” said Mary Poppins, looking over the arm of the sofa and sniffing.

      “Oh no,” said Michael reproachfully. “It’s for myself. I’m saving.”

      “Huh – for one of those aeryoplanes*, I suppose!” said Mary Poppins scornfully.

      “No, for an elephant – a private one for myself, like Lizzie at the Zoo. I could take you for rides then,” said Michael, half-looking and half-not-looking at her to see how she would take it.

      “Humph,” said Mary Poppins, “what an idea!” But they could see she was not quite so cross as before.

      “I wonder,” said Michael thoughtfully, “what happens in the Zoo at night, when everybody’s gone home?”

      “Care killed a cat,*” snapped Mary Poppins.

      “I wasn’t caring, I was only wondering,” corrected Michael.

      “Do you know?” he enquired of Mary Poppins, who was whisking the crumbs off the table in double-quick time.

      “One more question from you – and spit-spot, to bed you go!” she said, and began to tidy the Nursery so busily that she looked more like a whirlwind in a cap and apron than a human being.

      “It’s no good asking her. She knows everything, but she never tells,” said Jane.

      “What’s the good of knowing if you don’t tell anyone?” grumbled Michael, but he said it under his breath so that Mary Poppins couldn’t hear…

      Jane and Michael could never remember having been put to bed so quickly as they were that night. Mary Poppins blew out the light very early, and went away as hurriedly as though all the winds of the world were blowing behind her.

      It seemed to them that they had been there no time, however, when they heard a low voice whispering at the door.

      “Hurry, Jane and Michael!” said the voice. “Get some things on and hurry!”

      They jumped out of their beds, surprised and startled.

      “Come on,” said Jane. “Something’s happening.” And she began to rummage for some clothes in the darkness.

      “Hurry!” called the voice again.

      “Oh dear, all I can find is my sailor hat and a pair of gloves!” said Michael, running round the room pulling at drawers and feeling along shelves.

      “Those’ll do. Put them on. It isn’t cold. Come on.”

      Jane herself had only been able to find a little coat of John’s, but she squeezed her arms into it and opened the door. There was nobody there, but they seemed to hear something hurrying away down the stairs. Jane and Michael followed. Whatever it was, or whoever it was, kept continually in front of them. They never saw it, but they had the distinct sensation of being led on and on by something that constantly beckoned them to follow. Presently they were in the Lane, their slippers making a soft hissing noise on the pavement as they scurried along.

      “Hurry!” urged the voice again from a near-by corner, but when they turned it they could still see nothing. They began to run, hand in hand, following the voice down streets, through alley-ways, under arches and across Parks until, panting and breathless, they were brought to a standstill beside a large turnstile in a wall.

      “Here you are!” said the voice.

      “Where?” called Michael to it. But there was no reply. Jane moved towards the turnstile, dragging Michael by the hand.

      “Look!” she said. “Don’t you see where we are? It’s the Zoo!”

      A very bright full moon was shining in the sky and by its light Michael examined the iron grating and looked through the bars. Of course! How silly of him not to have known it was the Zoo!

      “But how shall we get in?” he said. “We’ve no money.”

      “That’s all right!” said a deep, gruff voice from within. “Special Visitors allowed in free tonight. Push the wheel, please!”

      Jane and Michael pushed and were through the turnstile in a second.

      “Here’s your ticket,” the gruff voice said, and looking up, they found that it came from a huge Brown Bear who was wearing a coat with brass buttons and a peaked cap on his head. In his paw were two pink tickets which he held out to the children.

      “But we usually give tickets,” said Jane.

      “Usual is as usual does.* Tonight you receive them,” said the Bear, smiling.

      Michael had been regarding him closely.

      “I remember you,” he said to the Bear. “I once gave you a tin of golden syrup.”

      “You did,” said the Bear. “And you forgot to take the lid off. Do you know, I was more than ten days working at that lid? Be more careful in the future.”

      “But why aren’t you in your cage? Are you always out at night?” said Michael.

      “No – only when the Birthday falls on a Full Moon. But – you must excuse me. I must attend to the gate.” And the Bear turned away and began to spin the handle of the turnstile again.

      Jane and Michael, holding their tickets, walked on into the Zoo grounds. In the light of the full moon every tree and flower and shrub was visible, and they could see the houses and cages quite clearly.

      “There seems to be a lot going on,” observed Michael.

      And, indeed, there was. Animals were running about in all the paths, sometimes accompanied by birds and sometimes alone. Two wolves ran past the children, talking eagerly to a very tall stork who was tip-toeing between them with dainty, delicate movements. Jane and Michael distinctly caught the words “Birthday” and “Full Moon” as they went by.

      In the distance three camels were strolling along side by side, and not far away a beaver and an American vulture were deep in conversation. And they all seemed to the children to be discussing the same subject.

      “Whose Birthday is it, I wonder?” said Michael, but Jane was moving ahead, gazing at a curious sight.

      Just by the Elephant Stand a very large, very fat old gentleman was walking up and down on all fours, and on his back, on two small parallel seats, were eight monkeys going for a ride.

      “Why, it’s all upside down!” exclaimed Jane.

      The old gentleman gave her an angry look as he went past.

      “Upside down!” he snorted. “Me! Upside down? Certainly not. Gross insult!” The eight monkeys laughed rudely.

      “Oh,