"What are you doing, Calibur?" Gregory asked his pet unicorn.

Calibur did not reply. He did not have to. Gregory could see for himself that Calibur was digging a hole in the back yard with his front hoofs. What Gregory did not understand was why Calibur was doing that.

"Uh, Calibur," said Gregory.

Calibur continued with his work as if Gregory were not even there.

"Calibur!"

The unicorn finally looked at his pet human and snorted with some irritation.

"Calibur," said Gregory, "how am I going to explain this to my parents? They'll ground me for a month and they'll ship you off to the glue factory!"

Calibur snorted to show that the question was not worthy of thought and continued to dig his hole. By this time, a large piece of the back yard had been dug up with dirt piled up all round the hole. Gregory looked back at the house nervously, sure that his mother would emerge from the back yard with the fury of a tornado, but nothing happened.

One thing Gregory had learned in life was that one could not argue with a unicorn. No project of Calibur's had ever turned out badly, although sometimes Gregory had feared one would. Reasoning that if he were going to be grounded for a month, he might as well earn it by having fun, Gregory walked to the shed, picked up a shovel, and brought it back to where Calibur was working.

Gregory was in for a surprise when he started to help Calibur with his task. There were other helpers as well! Little moles were digging tunnels in all directions from the main hole. Not only that, other moles were fitting support beams into place the way miners built them in their tunnels. Bemused with what was happening, Gregory pitched shovelful after shovelful of dirt out of the hole until Calibur nudged him. By this time, Gregory was so deep in the hole that he could not climb out. He looked at Calibur who, as usual, was not disturbed at all. Gregory looked at the moles who continued to work at a frenzied pace, and then noticed that mice and rabbits were also making tunnels and carrying supplies of food as if they were fleeing from some terrible calamity.

Calibur signaled for Gregory to climb up his back. From there, Gregory could easily climb out of the hole. His only concern was for Calibur, but he need not have worried. Calibur leaped out of the hole in one graceful bound.

The unicorn looked about him. Scores of chipmunks and squirrels and racoons were invading the back yard. All of the animals seemed very upset over something that had happened to them. The squirrels and chipmunks all had their cheeks swollen with food they had carried away from their homes.

Gregory thought the two of them had finished their project, but Calibur did not. Not only did Calibur trot over to the dock on the lake behind Gregory's house, he started pulling the boards up, one by one with his teeth. Gregory added several months to his sentence of being grounded, ran back to the shed for his hammer, and returned to help Calibur tear up the dock. After he was grounded, Gregory reflected, he would have time to build a new one, and he would enjoy doing that. Meanwhile, the raccoons picked up the loose boards and carried them over to the hole.

Gregory and Calibur tore out plank after plank of wood from the dock until it seemed that they had torn up all the docks in the world. But even when it seemed impossible for there to be any dock left, there was always at least one more plank left to tear out.

However, once Gregory had finished working for what seemed forever, Calibur suddenly forsook the project and galloped back to the hole. The raccoons had stacked the boards all around the hole. The rabbits were molding the dug up earth into what appeared to be the foundations for a house. The mice and moles had built supports all across the hole, and the squirrels and chipmunks were laying some of the boards across them. Gregory knew what to do. He ran back to the tool shed for some nails.

It was fun, nailing down the floor, and then building up the house, story by story. Calibur coached him by showing him where he wanted rooms divided, and where to put windows. As he needed them, the boards were brought up to him by the raccoons and some woodchucks and foxes who had also joined them. Everything seemed so natural to the animals, that Gregory did not think to question their participation. No sooner had he finished one floor, then several animals moved in with their supplies of food and made themselves at home.

Gregory soon lost count of how many floors there were to the animal house. At some point, the pieces of wood became smaller, and soon it was birds, and not raccoons, who were carrying up the pieces. There were cardinals and sparrows and nut-hatches and chickadees and blue jays and goldfinches and doves, and many other birds besides. The birds, too, were moving about frantically as if their lives were in danger. By this time, Gregory had been pounding in nails for so long that he began to doubt that there had ever been a time in his life when he was not building the house.

At long last, Calibur signaled Gregory to build a frame for the roof. The birds brought clumps of tall grass to make a thatched roof to it all. Gregory put down his tools and looked out the window. He was so high up, he could see for miles around and the house swayed a little in the wind. Off in the distance Gregory saw smoke. Perhaps somebody was having a bonfire. Gregory hoped so. Some of the birds offered Gregory some worms which they were eating. It was a nice thought, but Gregory politely turned down the offer.

With happy animals living in the house from basement to top floor, Gregory climbed back down to the ground. It was a long trip down. The animals chattered their appreciation for the efforts Gregory and Calibur had made on their behalf as they went. Once he was back on the ground and out of the house, Gregory looked up. The top was so high he couldn't even see it.

Gregory was hungry. He wanted to go back into the house and find some food. But he did not want to run into his parents and have to explain what he had done. Calibur was so undisturbed by such thoughts that Gregory felt envy towards the unicorn. Perhaps he would not have to face his parents if he could think of something else. Maybe he should just live so high up in the house he had built that nobody would ever find him. He could train the animals to bring him food he could eat instead of worms. Then he wouldn't ever have to explain anything.

But before Gregory could do anything about these thoughts, his mother called him in to supper as if everything were normal. Gregory looked at his mother who was standing in the doorway. Nothing in her face suggested she was wondering what that towering house was doing in the back yard. Gregory looked back. The house was gone! Not only that, the dock was intact, as if not even one nail had been pulled out.

"Have I been dreaming, Calibur?" asked Gregory.

But Calibur did not answer. He only trotted off to his stable where his own supper awaited him.

With his mind in a whirl, Gregory went into the house, washed his hands, and sat down at the table. Dinner that night was chicken and rice. Gregory poured himself a glass of grape juice. His brothers and sisters seated themselves with as much noise as possible. Gregory did not hear what they were saying. They were chattering as frantically as the animals in the house he had built, if he had built the house at all. Then his father came into the dining room and sat down. In a calmer voice that caught Gregory's attention, he said that there was a serious forest fire just three counties away.

"And all the animals have lost their homes!" cried Gregory's sister, Lucy. "Where are they going to live?"

But Gregory knew. And so did Calibur.