So, when the song was over, they flew to the Phenix, who was the most important and powerful bird of all the birds that were in Paradise. I have told you that all the birds there were equal, and so they were, only, you see, the Phenix was a little _more_ equal than the others. One cannot be a Phenix for nothing. Now it was only the Phenix who could open the gate of Paradise, and let any bird in or out of it. He was not obliged to let them in, and there were very few birds (who were not there already) that he ever did let in. Many and many a bird fluttered and fluttered outside the door, that had to fly away again. But if a bird that was in Paradise wanted to go out of it, then the Phenix had to open the door and let it out, because if it had stayed it would have been discontented, and birds that are discontented cannot stay in Paradise. It would not be Paradise for long if they could. So when the Birds of Paradise said to the Phenix, "Let us out, for we are tired of being here, where all are equal, and wish to be kings and 'prima donnas' on earth," he had to do it, only he warned them as the tree had done, that if they once left Paradise they could never come back to it again. "The door of Paradise," said he, "may be passed through twice, but only entered once. When you pass through it the second time, it is to go out of it, and when you are once out of it, out of it you must remain. You can never come in again; you can only flutter at the gate." "We shall never do that," said the proud Birds of Paradise. "We shall stay down on earth and be kings and 'prima donnas' amongst the other birds." So the Phenix let them out, and they flew down through the warm summer sky, looking like soft suns or trembling stars or colours out of the sunrise or sunset, they were so beautiful. Then the birds of earth flew around them and did them homage, and, when they sang, the nightingale stood silent and hid her head for shame, and would never sing in the daytime any more, but only at night when the beautiful strangers were asleep. That is why the nightingale sings by night and not by day--only since the Birds of Paradise have lost their voice (which I am going to tell you about) she does sing in the daytime sometimes, just a little.