“I’ll take you there,” he said. “I’ll give you some of my clothes to wear, and then I can smuggle you past somehow. I’ve been living here a long time. I know all the back alleys.”

“Would you really guide her?” asked Firedrake. “How can we ever thank you?”

Ben turned red. “Oh, it’s nothing. Really,” he muttered.

Sorrel was not looking so enthusiastic. “Human clothes,” she growled. “Yuck. Dismal death caps, I shall stink of human beings for weeks.”

But she put the clothes on all the same.

5. Gilbert the Ship’s Rat

“Which warehouse is it?” asked Ben. “If you don’t know the number, we could have a long search ahead of us.”

They were standing on a narrow bridge. Warehouses lined both sides of the canal: strange, narrow buildings of red stone, with tall windows and pointed gables. The harbor of the big city wasn’t far away, and a cold wind was blowing from that direction, almost tearing the hood away from Sorrel’s pointy ears. A great many humans were pushing past them, but no one stopped and stared at the small figure with Ben, clutching the railing of the bridge. The sleeves of Ben’s sweatshirt, which were much too long for her, hid Sorrel’s paws. His jeans, turned up twice at the bottom, hid her legs, and her catlike face was hidden in the shadow of the hood.

“Rat said it’s the last warehouse before the river,” she whispered. “And her cousin lives in the cellar.”

“Rat? You don’t mean a real rat, do you?” Ben looked at Sorrel doubtfully.

“Of course she’s real. What do you think? Don’t just stand there looking stupid, not that you don’t do it well, but we’ve got more important things to do.” She impatiently pulled Ben along after her. The bridge led to a narrow road running beside the bank. As they hurried along the pavement, Sorrel kept looking anxiously around. The sound of traffic hurt her ears. She had been in small towns before, stealing fruit from gardens, exploring cellars, teasing dogs. But there were no gardens here, no bushes where you could crouch down and hide in a hurry. Everything in this city was made of stone.

Sorrel was greatly relieved when Ben guided her into a narrow alleyway that led back to the canal between the last two warehouses. There were several doors in the red walls. Two were closed, but when Ben pushed the third, it opened with a slight creak.

They hurried in. An unlit stairway lay before them. Daylight filtered in through a narrow, dusty window and revealed one flight of steps leading up and another down.

Ben looked suspiciously down the dark steps. “There’ll be rats there, that’s for sure,” he whispered. “The question is, can we find the right one? How will we recognize it? Does it wear a collar and tie or something?”

Sorrel did not answer. She pushed back her hood and scurried down the steps. Ben followed her. It was so dark at the foot of the steps that he took the flashlight out of his jacket pocket. A cellar with a high vaulted ceiling lay before them, and once again he saw any number of doors.

“Huh!” Sorrel inspected the light and shook her head scornfully. “You humans need your little machines for everything, don’t you? Even to look at things.”

“It’s not a machine.” Ben swept the beam of the flashlight over the doors. “What are we actually looking for? A mouse-hole?”

“Don’t be silly.” Sorrel pricked up her ears and twitched her nose. Still snuffling, she moved slowly from door to door. “Ah, here we are.” She stopped in front of a brown door that was slightly ajar. Sorrel pushed it open just far enough for her to slip through the crack. Ben followed.

“My goodness!” he murmured.

The tall windowless room they entered was stuffed with junk up to the ceiling. Among shelves full of dusty folders stood stacks of old chairs, tables piled on top of one another, cupboards without doors, mountains of index-card files, and empty drawers.

Sorrel raised her nose, sniffing, then shot purposefully away. Ben banged his shin following her. He had already lost track of the door they had come through. The farther they went the more chaotic the clutter became. Suddenly some shelving units barred their way.

“That’s it, then, I suppose,” said Ben, letting the beam of his flashlight wander around the place. But Sorrel ducked, crawled through a gap between two shelves — and disappeared.

“Hey, wait for me!” Ben cried and pushed his head through the gap.

He was peering at a small study — a study just the right size for a rat, barely a meter away from him and underneath a chair. The desk was a book propped on two sardine cans. A coffee mug turned upside down did duty as a chair. There were index-card files full of tiny slips of paper, empty matchboxes stood everywhere, and the whole place was lit by an ordinary desk lamp standing on the floor beside the chair. But whomever it was who used this study was nowhere to be seen.

“You stay here,” Sorrel whispered to Ben. “I don’t think Rat’s cousin will be particularly pleased to see a human being.”

“Oh, come off it!” Ben crawled through the gap and straightened up. “If it doesn’t get a fright at the sight of you it won’t mind me, either. Anyway, it’s living in a human building. I don’t suppose I’ll be the first human it ever saw.”

“He!” hissed Sorrel. “It’s a he, and don’t you forget it.”

She looked around curiously. In addition to the little study area under the chair there was also a human-sized desk, a huge chest of drawers, and a large old globe of the world hanging at an angle on its stand.

“Hello?” called Sorrel. “Anyone at home? Oh, drat it, what was his name again? Giselbert — no, Godfrey — no, Gilbert Graytail or some such.”

Something rustled above the desk. Ben and Sorrel looked up and saw a fat white rat looking down at them from his perch on top of a dusty lamp shade.

“What do you want?” asked the rat in shrill tones.

“Your cousin sent me, Gilbert,” said Sorrel.

“Which one?” asked the white rat warily. “I’ve got hundreds of cousins.”

“Which one?” Sorrel scratched her head. “Well, we always just call her Rat. Wait a moment … I remember! Her name’s Rosa. That’s it!”

“You’ve come from Rosa?” Gilbert Graytail let down a tiny rope ladder from the lamp shade and quickly clambered down it. He landed on the big desk with a thump. “Oh, well, that’s different.” He stroked his whiskers, which were white as snow, like his coat. “What can I do for you?”

“There’s this place I’m looking for,” Sorrel told him. “Well, it’s a mountain range really.”

“Ah!” The white rat nodded, looking pleased with himself. “You’ve come to exactly the right person. I know all the mountain ranges on this planet, large, small, and medium. I know everything about them. After all, my informants come from all over the world.”

“Your informants?” asked Ben.

“Yes, ship rats, seagulls, the sort of folk who get around a lot. And I have a large extended family.” Graytail went over to a big black box standing on the desk, raised the lid, and pushed a knob on its side.

“That’s a real computer!” said Ben, surprised.