owhere to run, children,” said Mamba.

“Why did you kill her?” shouted Caw, pointing to Miss Wallace’s limp body. “She never hurt anyone!”

“We had to,” said Jawbone. His grin widened. “Not that we didn’t enjoy it.” He looked at the others. “Let’s finish the job, shall we?”

The short man sniggered and clicked his fingers.

Caw heard a strange chattering sound, then something dropped from the cuff of Scuttle’s trench coat. It darted across the ground. A cockroach.

Lydia stumbled back into Caw. “Gross!”

“There are more where that came from,” said Scuttle.

He closed his eyes, as if he was praying. Then insects began to pour from both sleeves in a hideous wave of black shells and wriggling legs. Hundreds of cockroaches, climbing down his clothes and landing on the floor. Caw gasped and stumbled backwards as they fell from Scuttle’s trouser legs too, piling on top of one another in an endless stream.

“Caw?” said Lydia, her voice a terrified whisper.

“That’s not possible,” he muttered. Where were they coming from?

The cockroaches swarmed across the ground, straight towards them. Lydia screamed. Caw grabbed her hand and yanked her towards a side door. The cockroaches veered after them in a squealing, rustling mass.

They’d almost reached the door when Lydia yelped, “Caw, stop!”

Caw skidded to a halt as she tugged him back. Then he noticed movement in the corridor beyond the door. Three huge shapes emerged, padding through the doorway. They were dogs, their bodies thick with muscle beneath short fur, yellow eyes glaring over wrinkled snouts. Deep growls reverberated from their chests and drool spilled from black lips drawn up over jagged teeth.

With their exit blocked, and the cockroaches sweeping towards them, Caw jumped on to a table and pulled Lydia up beside him. She gripped his arm hard, her eyes full of panic.

“Cockroaches can climb, you know!” she said.

The black slick of insects covered the table legs and crept over the edge. Caw kicked at them, scattering the first wave on to the floor. But more followed, closing in from all sides. Lydia jumped down from the table, and Caw leapt after her, landing with a crunch among the broken shells. Almost straight away, the cockroaches climbed over his feet and legs, in a tickling, scratching tide.

Caw hopped to the edge of the seething mass, crushing more with every step. He heard Lydia scream again, then something slammed into his side and he fell. Foul breath washed over him as he realised it was one of the dogs. Its forepaws pinned his shoulders and its weight crushed the air out of him. The dog’s jaws snapped and snarled centimetres from his face. He was sure at any second it would sink those teeth into the soft flesh of his cheek. He felt the cockroaches scurry off him, as if even they were afraid.

“I wouldn’t move, if I were you,” said Jawbone. Caw turned his head away from the teeth and saw that Lydia was pinned down too. The third dog was sitting obediently at Jawbone’s side, licking his hand. “My dogs could tear through your throat like candyfloss.”

The dog on top of Caw lowered its snout and growled. Caw froze, his eyes glued shut. He could sense the dog’s vicious hunger. It wanted nothing more than to rip him to shreds, but something was holding it in check.

The woman’s voice came next. “No crows to help you this time?” she said.

Caw opened his eyes again, and saw her standing beside Lydia, eyeing her like a curious specimen. Lydia’s chest was rising and falling rapidly, and her features twisted in disgust. A snake, just like the one that had killed Benjy, was coiled around Mamba’s arm. Its neck and head rested on her wrist and she stroked its scales with the points of her long black nails. Its tongue flickered, shivering in delight.

“What have you done to them!” cried Scuttle.

He was crouched over a patch of squashed cockroaches, scooping them into his hands and letting their broken bodies fall through his fingers. Tears ran down his face. The rest of the cockroaches seemed to have vanished as quickly as they arrived.

Who were these people?

The hunchbacked man glared at Caw and Lydia, eyes wet and angry. “Let me kill them!” he snapped. “Let my little ones crawl into their mouths and eat them from the inside!”

He staggered towards them, but the third dog blocked his path, snarling, ears drawn back.

“Not now,” said Jawbone. “Remember why we’re here.”

Not to kill us then. Despite his fear, Caw tried to think clearly. We’d be dead if that was their plan.

The dog on top of Caw suddenly lifted its head, its ears cocked. The other dogs copied.

A second later Caw heard sirens. Hope flickered in his heart.

“Cops!” hissed Mamba. “How did they know?”

Jawbone turned his massive head towards Miss Wallace’s corpse. He grunted. “She must have pressed the panic button right before she died.”

Cars screeched to a halt outside and through the frosted glass of the windows Caw saw the flash of blue and red lights.

“Help!” yelled Lydia. “Help us!”

“What do we do?” Scuttle asked, eyes darting around.

The door of the library thudded and the chains rattled.

“We go,” said Jawbone, calmly. His eyes fell on Lydia. “Bring the girl.”

Mamba and Scuttle rushed forward and Caw felt the weight of the dog lift off his chest. He rolled over, just in time to see Scuttle haul Lydia off the ground and throw her over his shoulder. She kicked and screamed, her red hair coming loose from its plaits. Caw lunged after her, but a stinging blow caught him across the cheek and he fell back against Miss Wallace’s desk, stunned. Mamba stood in front of him – he hadn’t even seen her move, let alone strike him. Close up, he saw her face in more detail. High cheekbones. Lips that were almost black. Eyes that glittered like precious jewels. She turned quickly and followed the others.

Jawbone reached into his pocket and pulled out something the size of an apple. He clicked a button on the top and tossed it spinning into the middle of the room. A rush of smoke poured out, spreading quickly from the ground up.

“Get off me!” cried Lydia.

Caw scanned Miss Wallace’s desk and saw her paperweight. He snatched it up, took aim and hurled it across the library. It hit Scuttle’s head with a sickening thud and the man fell to his knees, letting go of Lydia. She scrambled away, as Mamba rushed to Scuttle’s side. Moments later they were hidden by smoke.

“That little wretch!” snarled Scuttle. “Where’d she go?”

“Leave her!” came Jawbone’s voice. “We can’t afford to get caught.”

Caw heard a bang and through a gap in the drifting smoke he saw the front doors burst open. A cop went down on one knee as light flooded in. Torch beams lit up the smoke, and shouts filled the air.

“Police!”

“Don’t move!”

Caw froze beside Miss Wallace’s body. He spotted Lydia’s shadow moving between the shelves ten metres away.

A torch dazzled him.

“Hands where I can see them!” yelled a cop.

Caw ducked and plunged into the waves of smoke. A single gunshot cracked and the shelf beside his head exploded into splinters. Two more bullets whizzed past and smacked into the wall.

“Wait!” said Lydia.

By the time he reached her side, Caw could barely see a thing. He sucked in a lungful of the acrid smoke and coughed, his lungs burning.

“Come on!” he said, tugging Lydia towards the door the dogs had emerged from.

More shots ripped through the air overhead.

“Hold your fire!” shouted a voice. “There might be hostages!”

The gunfire stopped as Caw dragged Lydia along the corridor. They passed several doors before they reached a set of stairs leading downwards. He took them three at a time, and Lydia stumbled after him. At the bottom Caw pushed open a door with a picture of a man on it and found himself in a bathroom. There were windows at head height over the sinks.

“Caw, stop!” said Lydia. “The police are on our side.”

“No they’re not!” said Caw. He climbed up beside a sink and opened the window lever, but couldn’t budge the pane. He slammed a palm into it.

“We’ll just explain what happened! They’ll believe us!” said Lydia. She wasn’t climbing up beside him.

“Help me!” said Caw, punching the window frame again. It gave a fraction.

Lydia looked back towards the door. “Caw, they’ll think we’re guilty of something if we run!”

Caw drew his hand back and whacked the window again. It opened about half a metre and dried paint flaked off the frame. He held out his hand to her. “Please Lydia,” he said. “You don’t understand. If they take me in, I’ll never get out again. They’ll put me in an orphanage.”

Lydia stared at him, and softened. She knew it was true.

Caw took her hand and helped her up. “You first,” he said.

Confused voices sounded from outside. “Take it one room at a time!”

“Extreme caution, they might be armed!”

“Room clear!”

Lydia squeezed through the gap and Caw boosted himself after her. He heard the bathroom door slam open and dragged his body out on to the gravel outside. He didn’t look back as they ran across the car park, past Miss Wallace’s car.

“Hey you!” cried a voice. “Stop!”

An engine revved and a police car slewed across their path. Two cops jumped out. One reached for his gun, but before it was out of the holster Screech swooped down on to his arm. The cop jerked back with a wail of surprise as Glum snatched the hat from his head. Lydia ran past, towards an alleyway. The other cop spread his arms wide to catch Caw, bending slightly.

“You’re not going anywhere, kid!” he said. Caw ran full pelt at him, and for a strange second he felt almost weightless, like he was a crow himself. He jumped high, his legs connecting with the policeman’s shoulder, and the world turned upside-down as he tumbled head over heels.

Caw landed on his back on the car bonnet, sliding off the far side. The cop turned, eyes wide in amazement, as Caw ran after Lydia with his coat billowing.

Moments later he heard the pounding feet of the cops close behind them.

An enormous flock of pigeons was feeding on the ground ahead and Caw plunged straight through them. The birds took flight in screeching panic, and when Caw looked back he saw the cops fighting their way through the flapping wings.

Above them soared two black shapes – Glum and Screech.

“Which way?” said Lydia.

Screech and Glum veered left ahead. “Follow the crows!” said Caw, pointing.

They ran at full pelt through the twisting alleys of the rundown riverside districts of Blackstone, the crows always just ahead.

By the time they stopped running, they were by a junction with one of the main roads running north. Sirens occasionally wailed nearby, but they had lost the cops. Caw’s breath was ragged and Lydia was bent double. “That was … some jump,” she said. “Sure you didn’t spend time in the circus?”

Caw shook his head. He didn’t know how he’d done it. He just … had.

Glum flapped to the ground at their feet, while Screech landed on the awning of a café opposite.

“You came,” said Caw.

I didn’t want to, said Glum, with a haughty lift of his beak, but Screech convinced me. Lucky for you.

“Tell them thank you,” said Lydia.

Tell her we don’t need her thanks, said Glum. Caw, can’t you see she’s dangerous?

“What did he say?” asked Lydia.

“He said, ‘Think nothing of it’,” Caw lied.

Enough, Caw, said Glum. This road leads back to the park. Say your goodbyes.

“We should go to my father,” said Lydia. “He’ll know what to do.”

Absolutely not, said Glum. Don’t listen to her.

“I can’t,” Caw said. “He won’t understand.”

Lydia blew a strand of hair out of her face. “Then we’ll make him,” she said. “He’s not the police. He’s not against you. And he’s my dad!”

You can’t trust him, said Glum.

Lydia flashed an annoyed glare at the crow, almost as if she understood his squawks.

“My dad’s not interested in you, Caw,” she said. “He wants those convicts.”

Caw knew Mr Strickham wasn’t a bad man, but he wasn’t a friend either.

“Don’t you see?” Lydia urged. “We need people on our side. We don’t have to face this on our own.”

You’re not on your own, said Glum. You’ve got us.

Caw shook his head and stared at the crow. “You saved us, Glum,” he said. “I know you did, but there’s something big going on here. They killed Miss Wallace. And that spider from my dream had something to do with it. It was painted on the wall, and … they put a spider’s web over her mouth.” He felt a lump in his throat. “She must have been so afraid,” he mumbled.

Glum cocked his head and looked upwards. Caw followed his gaze and saw Milky for the first time, standing on the rim of a satellite dish.

“When did he get there?” asked Caw.

He’s been watching all along, said Glum.

Milky gave a soft warble that Caw hadn’t heard before.

Screech flew over and landed on Caw’s shoulder. Did you see the way I got that cop? he said. Kapow!

“I saw,” said Caw. He smiled sheepishly. “I’m sorry for what I said earlier. I don’t deserve your help.”

As they emerged on to the main street, Caw saw a pigeon standing on top of a streetlamp.

“The pigeons helped too,” he said, looking up into the bird’s unblinking eyes. “Didn’t they?”

A fluke, said Screech. He gave a couple of harsh squawks and the pigeon took off.

Caw lost himself in his thoughts while they hurried towards Lydia’s house. As the adrenaline of the chase seeped away, his heart became heavy.

“You’re not to blame, you know,” said Lydia, as though she’d guessed what he was thinking. They were both keeping a lookout for any sign of the police as they hurried down a deserted side street. The crows flew ahead to the road junctions, squawking twice if the way was clear, once if not. Caw and Lydia frequently ducked behind parked cars, just in case.

“She’d be alive if it wasn’t for me,” said Caw. “I felt like we were being followed the first time we went to the library. It must have been those prisoners. Maybe if I hadn’t asked her to help …”

At the back of his mind lurked another question. Who, or what, was Quaker? And why was the word so important that Miss Wallace kept it in her hand, even as she was being killed?

Lydia took hold of his arm. When he looked up, he saw her gaze pleading with him. “Caw, those three prisoners killed Miss Wallace, not you. And when the police get them, my dad will lock them up and make sure they never get out again. All right?”

Caw was grateful for her words, even if he wasn’t really convinced by them. He felt a sudden fierce rage burning through his chest. Those murderers deserved worse than a prison cell. A lot worse.

After a few more turns, the walls of the park appeared at the end of the road and then the Strickham’s house came into view.

“Are you sure about this?” asked Caw, feeling suddenly apprehensive. “I mean, your parents don’t exactly like me, do they?”

“It’s not that,” said Lydia. “You’re just a bit … different.”

Charming, said Glum, swooping overhead. We’ll wait here.

The three crows landed in the branches of the beech tree, Milky a branch higher than the others. His pale eyes seemed to follow Caw. The day had turned chill, with grey clouds amassing in the sky.

Mrs Strickham flung open the door before they were halfway up the drive.

“Where have you been, young lady?” she asked.

“Mum, we need to speak to Dad,” said Lydia.

“Your father is on the phone,” said Mrs Strickham. “And what is that boy doing here again?” Her eyes snagged on something beyond Caw and she paled. Caw turned and saw that she was looking at the crows. “Get inside,” she said.

Lydia walked up the steps.

“Just you, Lydia,” said her mother, as Caw tried to follow.

Lydia stopped. “He’s my friend. I’m not coming in without him.”

Caw felt a rush of pride. No one had called him their friend in his entire life.

Mrs Strickham opened her mouth, but hesitated, as though she wasn’t sure what to say. Her expression shifted, and all of a sudden she looked more sad than angry.

Mr Strickham appeared behind her, his phone to his ear. “Thanks, John,” he was saying. “Keep me in the loop.” He looked haggard as he hung up, but his face came alive when he saw his daughter. “Lydia – thank goodness you’re safe.” His eyes flicked over to Caw nervously, and he turned to his wife. “DI Stagg says there’s been some sort of … incident at the library. Apparently the commissioner’s taking a particular interest in it.”

“I know,” said Lydia. “We were there.”

Mr Strickham did a double-take at his daughter. “You were what?” he snapped.

Caw stepped forward, trying to look bold. “We saw the killers, sir. It was those escaped prisoners.”

“Tony!” pleaded Mrs Strickham. “This boy …”

“Let him in,” said Mr Strickham. “It sounds like the pair of you have some explaining to do.” Mr Strickham muttered something to his wife. Then he turned back to Caw. “Could you wait in the lounge a moment while I talk to Lydia alone?” he said.

Caw nodded, and Mr Strickham led him into another huge room, this one with plush sofas and a fire burning in the hearth. There was a set of double doors leading to a wrought-iron balcony overlooking the back garden, and beyond that, the hulking shape of the prison. Mr Strickham gestured to a sofa and switched on the TV as Mrs Strickham came in with a glass of water. She handed it to Caw without a word then left again. Mr Strickham fiddled with the remote and the sound got louder. A woman was talking about fuel prices.

“I’ll just be a minute,” said Mr Strickham. He left the room, closing the doors behind him.

Caw sipped the water, trying to clear his head. What had those convicts wanted in the library? Not to kill them, that was for sure. But what they’d done to Miss Wallace showed how merciless they could be. How were they connected to the spider?

And what about ‘Quaker’?

The woman on the screen touched her ear and a piece of paper was handed to her by someone out of shot.

“This just in,” she said. “Police are reporting a suspicious death at Blackstone Library. The victim has been identified as Miss Josephine Wallace, Head Librarian for the last decade. Police are keeping an open mind as to motive at this time, but anyone with information should contact …”

A tapping at the window made Caw look up. Screech and Glum were perched on the railing of the balcony outside.

Caw went quickly to the window doors. They were locked and the keyhole was empty. He put his mouth to the small hole.

“What is it?” he said.

Milky’s worried about you, said Screech. He doesn’t trust them.

“Who? The Strickhams?” said Caw. “Did he say that?”

Sort of, said Screech.

“Sort of?” Caw said, rolling his eyes. “Look, I know you don’t like Lydia, but she’s on my side. And I think her father is too.”

Really? said Glum. In that case, why has he locked you in?

Caw’s blood ran cold. “He … he hasn’t.”

Try the door then, said Glum.

Caw left the window, crept around the sofa and placed his fingers on the door handle. When he pressed down, it didn’t move.