“But I must have it to pass the gates.”

“Well, you can show that it’s empty,” he said. “We must chance it. Come on.”

They crept out into the deserted corridor, where all was silent save for a snorer in one of the near-by rooms. They crept to the stairs. All seemed silent on the landing below. On the next floor they heard a child wake up with a whimper. The coarse voice of a nurse from one of the French-speaking islands called “Chocolat” to quiet it. As this failed she made a testy reproof and turned grunting out of bed.

All seemed silent on the floor below. Rosa touched Hi’s arm at the stairs.

“There’s a night porter asleep there,” she said, “on that sofa on the landing.”

“He’s sound asleep,” Hi said. “Come on.”

On the third step from the bottom the porter had left a small tray with glasses and a soda-water bottle. Hi trod upon this, so that both he and it fell. The glasses broke, the soda-water bottle rolled on to the broad uncarpeted steps which led to the ground floor. It fell on to the first step, then on to the second, then on, step by step, making a noise like “Keblonk, Keblonk” at each step. Hi sat on the mat at the stair-foot in fits of laughter. Rosa stood beside him, giggling hysterically.

“Hark at the beastly thing going ‘Keblonk,’ ” he said.

With a little tinkle the bottle rolled itself still. The porter on the sofa sneezed suddenly and sat up.

“Oh, for de Lord,” he said.