THIS COULDN'T BE HAPPENING.

Suria fanned her arms out in front of her, and soft pink light fluttered between her fingers. She summoned a wave of energy and sent it crashing down the corridor. The guards steeled themselves against the onslaught, but while they were occupied, Ren leapt into the air, landing behind their line.

"Ren, wait!" Mori cried. "Don't let her do this!" 

But Ren barely looked in his direction before escaping into the system room.

"Hold her off!" Terza commanded, before turning and following Ren inside. Cursing under his breath, Mori followed, leaving the battle to rage outside.

He hovered inside the system room amidst the rolling gears. Terza chased Ren through the tower, but Ren seemed faster, nimbler. He realised with a start that Ren would almost certainly destroy Mesembria as well if she wasn't stopped.

Now, now...this won't do at all.

The voice sounded at the back of his mind. The voice of the void. Mori jumped.

"How...?" Was all Mori could ask.

The tower's energy is my own energy. As soon as you brought it into the void, I was able to escape.

Mori started, remembering the chill in the synchroniser once he'd returned from the void. "You've been in the timepiece the whole time?"

The voice laughed. Yes, but you have more pressing problems right now. Ren will destroy this tower – my tower – if left unchecked.

Since you were kind enough to bring the energy from one of my towers into the void, I will do this as a favour for you. Something rumbled at the back of his mind. Let me out for a moment. I will sort this out.

Mori hesitated. For some reason, Argent's words about trust rose up in his head. "I'm starting to think there was a reason you were stuck down there."

Why this hostility, Mori? The voice crooned. You were trapped down there of your own accord. I was kind enough to offer a way out.

The kind thing would have been to let us out with no strings attached. You would have had us down there forever if I didn't have a way to stop you.

It had to be done. Some laws are inviolable.

Mori snorted. "I thought your power was absolute."

Mori felt the ice in the void's words. My patience grows thin, Mori. And you have little time. How long will you wait before another tower collapses on your account?

Mori stiffened. The void was right — this wasn't the time to be obstinate. But still, something about letting it out here made his blood chill.

"I want an agreement," Mori muttered. "You're fond of those, aren't you?"

A long sigh echoed in his mind, like a gust of wind in his mind. Very well, if you insist.

"I'll let you out, for one minute. Then you return back to the watch. That seems fair."

One minute? That hardly seems—

"We could go down to forty seconds, if you'd prefer."

A minute then. The voice tutted. Bargaining with a clockmaker. This is beneath me.

Above them, Ren hit Terza with a blast of light. The older clockmaker flew back through the system, slumping against a core gear.

Hurry, the voice urged.

Mori frowned. "What do I do?"

Just open the timepiece. Quickly, now.

Mori flipped the cover open. The air around them seemed to darken. Shadow slicked out from the clock face, coalescing into a familiar, scratchy figure. It tipped its head back and let in a long deep sigh.

"Ah, it feels good to be back."

Mori glared at it. "Remember our deal."

"Of course, of course." The figure raised its arms. A shimmering veil of darkness rose up from the bottom of the system room. It slicked over the gears of the tower, holding the system in place. "There. I've sealed the Tower of Shadows. Nobody will be able to modify it for a short while."

Mori breathed a sigh of relief. "Okay." He extended the timepiece. "Well, get back in."

The figure's smile grew. "I have a minute, as we agreed. Two seconds to safeguard the tower." Its long fingers trailed across the gear train, as if searching for something. "That leaves fifty-eight to destroy that infernal timepiece." A sinister smile crept over its face. "And then an eternity of freedom. A fair deal, wouldn't you say?"

"What?"

The figure raised its arms again, and this time streams of dark energy shot from the gear system, filling the synchroniser. It trembled in Mori's grasp, shuddering with power.

Mori glanced round the system room, thinking frantically. Come on, come on...

All he knew was that the void was drawing power from the tower to destroy the timepiece. Mori touched his pocket: the traveller's timepiece was still there. Maybe...if he got to the bottom of the tower fast enough, he could stop it. Maybe jumping tower would be enough to stop the flow.

There was no time to doubt himself. Mori ran to the edge of the core gear and leapt, but the figure reached out and grabbed his cloak.

Going somewhere?

Mori clawed at its amorphous arm, trying to free himself. He felt each second tick by like a physical entity. The synchroniser rattled, unable to contain the energy flowing into it. Light cracked the cover, fracturing across the metal surface.

Mori twisted and wrenched his body, sharp enough that that clawed grip on his cloak ripped straight through it. Mori plunged through the Tower of Shadows, jumping from gear to gear to gain speed. The claws reached for him again, but Mori saw it coming this time. He twisted to avoid them, winding up the sundial he'd taken as he fell. The shield glimmered around him for a moment, effortlessly deflecting the figure's attempts to grab him.

Eyes flashing, its mouth pulled back into a vicious snarl. "You impudent little—"

The ring of light at the base of the tower swam up to meet him, fast. Too fast.

There was no time to slow down. Mori hit the ground like a punch to the stomach. He felt something crunch beneath him as he landed. Sickening pain shot up his legs when he tried to move.

In his hands, the cover of the timepiece started to crumble away. "No," he muttered, tightening his grip on the watch, trying to hold it together.

I'm out of time.

Mori clenched his fingers into fists and gritted his teeth. He crawled towards the slot in the centre of the platform, wheezing with pain every time he moved his injured leg. His vision swam, but the gold lines of the circle guided his fingers to the centre. He pressed the timepiece into the slot and twisted the rim with a trembling hands.

The metal of the pocket watch started to burn his skin. "Come on," Mori muttered, turning the rim again. The synchroniser flared with light that split the cover. The metal burned and crumbled away, exposing its cracked face. A triumphant shout echoed, roaring in his ears like a gale.

Then the timepiece clicked into place, and the ground opened up beneath them. Mori clutched the fracturing timepiece in his hands, as if trying to hold it together through sheer willpower alone. The space around him expanded, swirling black and blue and silver and gold. His stomach lurched as he bridged the gap between the clock towers — he thought he saw Elete flash by — the silhouette of the fractured tower, the fragments of a former world — before hazy sunlight swam into view. Warmth blossomed across his skin. The sunlight stretched out to claim him in an embrace and swallowed him whole, vision blinding with light—

— and he landed with a gasp. Soft air swirled around him, shimmering with the warmth of summer evenings and blossom fragrance.

I must be back on Hesperis.

Mori unclenched his fingers. The pocket watch lay in the centre of his palm, cold to the touch. Its cover had all but crumbled, and the watch face was shattered, but he heard the gentle ticking emanating from the mechanisms inside and gave a gentle sigh of relief. Black lines streamed from the clock's centre. Mori followed their paths, away from the watch, across the floor—

He froze. The dark figure stood opposite him, marred by the sunlight. Mori jerked back with a cry. How?

He realised what happened. The minute was up, but the synchroniser was too badly broken to pull it back inside. The figure marched across the space to him. Each footstep cracked the ground and cracked the air with a trembling thunderclap. In its white eyes shone a fury Mori couldn't describe. He felt it burn through him like a hot poker driven though his chest.

Mori tried to scramble away, but agony pierced his leg as he moved. A second later, the figure drove its foot hard into Mori's knee. The bones in his leg cracked beneath the force. Mori's entire body spasmed, his scream of pain strangled into a hoarse gasp.

The figure raised its leg again, aiming for another kick, but a bolt of purple light fizzled from behind a nearby building, shearing a hole through the figure's body. It spun round with a snarl. Another blast tore through its hand, then a third burned away its shoulder. With a cry of rage, the figure shrank away, violet sparks fizzling across the holes in its body. It slunk back into the timepiece.

Junot hurried over, purple still crackling at her fingers. "Are you okay?" She peered down at Mori, her eyes wide with concern. "What happened?"

Mori slumped back against the ground. He tried to say something, ask why she wasn't trying to kill him this time, beg for the pain to stop, but his mouth was dry. His words came out as a hoarse gasp.

Argent appeared beside Junot, shaking his head with a sigh. He crouched beside Mori and pushed his hair away from his face.

"Hey, take it easy," he murmured. "You're safe now."