The staircase dropped ten feet before turning at a sharp angle, the steps worn smooth by countless passages over what must have been decades. The air grew increasingly stale and thick as they descended and the walls soon transformed from dressed stone to rough-hewn rock.

“Twenty feet down,” Shaw murmured. “We’re well below the Institute’s foundations now.”

The staircase ended abruptly at a narrow passageway lined with ensconced brackets for torches long since extinguished. Evander augmented the fireball and sent it ahead to illuminate their path.

“This architecture predates the Institute.” Rufus frowned and ran his fingers along the ancient stonework. “These are Tudor-era construction techniques, possibly even earlier.”

“It’s probably part of the original arcane academy,” Evander said tightly. “Shaw, do you have the map?”

“Hang on a minute, your Grace.”

To everyone’s consternation, the forensic mage reached discreetly inside her cleavage and slipped out the copy of the facility blueprint Richfield had made for them before they’d left Scotland Yard.

Shaw blinked innocently at their shocked stares. “What?”

“Was there nowhere else you could have kept that?” Rufus asked testily.

“I was afraid it would fall out of my coat,” the forensic mage said with a dismissive shrug. “Besides, there’s nowhere safer than my bosom. Ask the chap who tried to cop a feel the other day.”

“Was that the man with the broken fingers you hauled into the Met?” Sergeant Griffiths grunted.

“Exactly,” Shaw confirmed smugly.

Evander sighed and took the overly warm map off her before forging ahead.

The corridor branched several times, the vile power they’d sensed in the lecture hall intensifying as they progressed farther inside the complex. They finally reached a heavy iron door after what felt like an eternity navigating the subterranean maze.

Unlike the ancient stonework surrounding it, it was undeniably modern—crafted from burnished metal, it was inscribed with arcane symbols that glowed faintly in the presence of his flames.

“Is it another ward?” Rufus asked edgily.

Evander lowered his brows. “Yes.”

He examined the intricate patterns etched into the metal before pressing the seal ring against the centre of the door, where the symbols converged. A series of mechanical clicks echoed around them as the complex locking mechanisms disengaged.

“Let’s hope no one on the other side heard that,” Shaw muttered.

They tensed when the door swung open on silent hinges.

A gloomy, empty corridor lay beyond.

“Engage your offensive magic,” Evander quietly told the assembled officers and mages.

Runes and spells came to life behind him, the power crackling the air making the hairs on his nape stand on end.

Evander’s heart raced as he stepped inside the enemy’s lair, the others following silently in his wake.

Rooms appeared on either side of the passageway, the shadows within them retreating as he cast light into the far corners.

Some had sleeping cots and desks. One hosted a kitchen with a dining table. There was even a washing facility.

“Looks like people have been living down here, your Grace,” Shaw whispered.

Evander clenched his jaw at the thought of all the evil that had played out in this place, deep beneath an Institute that was meant to guard against the very horrors it represented.

A low hum started vibrating through the floor as they advanced.

Evander stiffened and stopped when the amulet against his chest grew warm and began glowing with a pale light.

Rufus’s wary gaze found the pendant. “Is that?—?”

“Yes,” Evander said in a hard voice. “There are shadow creatures close by.”

A fraught hush fell around him.

Another door appeared up ahead. Unlike the first one, it wasn’t warded.

Cold fingers danced down Evander’s spine when he sensed the foul energy seeping around the hinges. He pressed his ear against the cold metal. No sound came from beyond it.

“Get ready,” he warned.

He closed his fingers on the handle and swiftly pulled the door open.

The chamber beyond was vast, its ceiling lost in obscurity despite the illumination from Evander’s flames.

A burning chill raised goose bumps on his skin, the acrid taste and stench of corrupt magic so abominable it scorched his tongue and nasal passages and made his eyes water despite his defences.

Several officers and mages gagged and threw up. Griffiths pressed a hand to his mouth and nose, his face ashen.

Evander erected a protective barrier of wind and fire magic around them. It cleared the air and made it easier to breathe again.

“Your Grace!” Shaw barked.

There was movement above.

A shadow creature was dropping silently towards them, its maw opening to gargantuan proportion. Evander scowled when he spotted the writhing mass of monsters hiding near the ceiling behind it.

The shadow creature screeched and recoiled when the power in the amulet reached it, the dark tendrils making up its form beginning to unravel.

It was all the time Evander needed to obliterate it with his fire magic.

The mages behind him cast a barrage of attacks at the remaining shadow creatures where they writhed and flickered in the air, temporarily weakened by the magic contained within the pendant around Evander’s neck. His ice spears ripped the last monster to shreds that vanished with a fading shriek.

Ice chilled his veins when he finally got a look at the chamber the creatures had been guarding.

Row upon row of workbenches stretched before them beyond a shallow landing, each cluttered with arcane instruments, glass containers, and meticulously labelled specimens.

The smell that had bothered Evander on the stairs was stronger here, rising even above the lingering dark magic.

He now recognised it for what it was—antiseptic mingled with pure evil.

“What in God’s name?” Rufus breathed.

Evander negotiated the short flight of steps and approached the nearest workstation. His stomach churned at what he found.

Anatomical diagrams had been pinned to a board, depicting the nervous system of what appeared to be a common house cat—except the annotations detailed how magical energy had been channelled through its body, with corresponding notes on the resulting physical changes.

“They were experimenting on animals,” Shaw said, horror evident in her voice as she examined a series of glass jars containing preserved specimens sitting on a shelf.

Evander’s nails dug into his palm. “These were probably precursor studies to test their theory.”

Shaw met his gaze and swallowed. “You mean, before moving on to human subjects?”

Evander nodded, too incensed to answer.

The Met’s officers and mages stared aghast at their frightening discovery. Evander could see anger replacing shock on many of their faces. Whatever their personal beliefs and opinions about magic users and thralls, they had all sworn to protect the people of this city.

They moved methodically through the chamber, uncovering the grotesque evidence of experiments spanning what must have been years of secret research.

Some of the journals they found dated back more than a decade, suggesting the programme had begun long before Whitley and Chevalier had become involved.

“Evander,” Rufus called urgently from the other side of the room. “You need to see this.”

Evander hurried over to where the inspector stood before a glass-fronted cabinet that contained dozens upon dozens of vials. His eyes widened at the sight of the silvery liquid they contained.

“That’s arcane residue!”

The vials bore markings indicating their contents: fire, water, wind, earth, light, shadow, and even a handful of esoteric magics Evander had only read about in ancient texts. His gaze landed on a shelf.

The sight of the labels made his heart thump violently inside his chest.

The vials were devoted entirely to different kinds of hybrid magic.

“What’s all this, your Grace?” Griffiths asked in a guarded voice as he approached.

Evander briefed the sergeant about Ambrose Mortimer’s autopsy findings.

Griffiths paled. Horror rounded the eyes of the officers and mages who’d followed him.

“You mean,” one of them quavered, “all these vials represent failed experiments?”

Evander could see the sickening truth he’d already reached dawning on their faces.

“Probably.” He studied the cabinet and its contents with a scowl. “And if that is the truth, then each of these vials likely represents a dead animal or person.”

A sound from beyond the laboratory had them all freezing. The low, mechanical hum that had brought them there was growing louder, the buzzing punctuated by the gurgle of liquid flowing through pipes.

“Your Grace, there’s another door!” Shaw hissed from the far end of the laboratory.

Evander and the others joined her swiftly.

A cold, blue light spilled under the door she had discovered, along with the smell of corrupt magic. Low voices came from beyond, their tone strangely rhythmical, as if they were chanting.

Tension knotted Evander’s shoulders. He glanced at his companions and signalled with his hand.

“In five,” he mouthed.

They nodded, determination filling their faces as they grasped their weapons and manifested their powers.

Evander gathered his magic protectively around him and was silently counting down when startled cries suddenly erupted on the other side of the door. An explosion boomed an instant later. The blue glow under the door shifted to crimson.

Fear choked his chest when he recognised Leon and Viggo’s voices in the aftermath of the detonation.

He kicked the door open, heedless of losing the element of surprise. A revolting, metallic tang of dark magic mired with Blood Magic washed over him and caused him to gag. The amulet around his neck flared white.

Evander pressed a hand to his mouth and nose and froze, the sight before him making the air lock in his throat.