Not many parties begin in full swing, but Gypsy’s and Ginger’s did. The moment the children of London saw Trafalgar Square, a dream of balloons and roses under the blue moon, they began to laugh; and for two hours, whether they were dancing to the organ music as only London Children can dance: or watching Punch thwack Judy as only Punch can thwack: or eating crumpets, and strawberries, and free ice-creams: or besieging the Weatherhouse for Jeremy’s free toys, or lying on their stomachs over the fountains with their faces in the sherbert: or playing Touch-Stone with Lily, Rose and Jessamine around the Column: they never stopped laughing. When the Taxi-Man appeared astride of Snow-Flame, and put him through his loveliest circus-tricks below the fairy lights, their laughter was louder than ever. And when Gypsy, inspired by the sound of it, painted this sign in luminuous paint on the National Gallery: THERE IS NO TRUTH IN THE RUMOUR THAT CHILDREN’S PARTIES WILL BE HELD IN TRAFALGAR SQUARE ONCE A WEEK their laughter was so loud that it was heard from Land’s End to John o’ Groats. It was so loud that it was heard by the Policeman in the Strand. He blew his whistle. In a trice the London Police were on the alert. [Illustration: GYPSY AND GINGER MOVE ON] When the Policeman on the Strand Beat blew his whistle, it was heard by every Policeman on every confine of London. But it was not heard in Trafalgar Square, because the party was by this time at its height. And while the Moonshiners sang and danced and rioted with the children, the policemen were answering the summons from Ealing to Barking, and from Crowdon to Crouch End. Through the silent streets they streamed in hundreds, like blue fire streaming noiselessly around a Christmas Pudding. From all points of the compass they converged on Trafalgar Square. Before they knew it, the Moonshiners were encircled. It was the Night Watchman who gave the alarm, too late. Even he had been caught napping for once. He had been competing at Catherine Wheels with the Evening Newsboy when he ought to have been keeping an eye on the night. But now, as the foe advanced in massed formation through Pall Mall and Whitehall, the Strand and St. Martin’s Lane, he scented them like a hound and cried: “The Police!” Dead silence fell upon Trafalgar Square. Only the ex-Professor made any demonstration, and that was a mute one. Meekly, yet carelessly, he bowed to right and left. “What are we going to do?” whispered Ginger. The Moonshiners drew together and consulted. The Taxi-Man was for defying the foe, but Ginger said, “Think of the children.” The Piccadilly Flower-Girls were for diddling the foe, but “There aren’t enough of you,” said Gypsy. “P’raps if we kep as still as mice,” said Rags, “they’d jest go away and not notice.” But the Night Watchman looked at the thousands of children and roses and balloons, and at the luminous sign on the National Gallery, and said,