She hoped a lot of things.

Electrolysis. The idea had struck her like one of the Sentinel’s laser beams. It was the process that was used for metal plating, and chromium was used to plate other metals all the time. Using a battery, she could alter the charge of the neutral atoms at the box’s base. The atoms would lose electrons, turning them into positively charged ions, which would dissolve right off the box. Over time, the positive chromium ions would move through the solution, attracted by the electrons that were being pushed out from the other side of battery, and be turned back into solid metal on the surface of the wheel.

The result: no more chromium box.

Or, at least, a big hole in the chromium box.

As an added bonus, she might even have a newly indestructible chromium-plated wheel once the process was complete.

It was so simple, so obvious, she couldn’t believe she hadn’t thought of it before. She’d even begun to wonder whether the Captain himself could be weakened this way, although it would be considerably more difficult to hook him up to a battery or dunk him into a vat of chemicals.

She attached the conductors.

Crossing her fingers, Nova switched on the battery.

And hoped.

She half expected the battery to flare to life with sparks and the sizzle of energy, but of course it didn’t. Only the digital readings on its side indicated that amps were flowing through the system. Nova adjusted the dials, increasing the voltage.

She inspected the wheel, not really expecting to see any visible change. The process would take time.

“A watched cathode never plates,” she muttered to herself, then pushed the entire electrolysis cell back into the shadows of the shelving unit.

She would let it run for an hour, she decided, before coming to check on it. She knew it could take all day before there would be visible signs of the chromium eroding. Which was fine. Ace had gone without his helmet for a decade. If he could be so patient, then so could she.

As long as it worked in the end. And as long as she kept Callum or Snapshot from coming to check on the restricted collection while the process was underway. She wasn’t entirely sure how she would accomplish that, but she was considering a toxic chemical spill in the next row. Or maybe she could orchestrate a diversion on the other side of the vault. A few broken jars of radioactive rocks would keep them busy for a while …

Brushing off her hands, Nova set the bucket on the cart and started to wheel it away, leaving the chromium box and her experiment behind.

She was nearly to the end of the aisle when a sound made her ears prickle. It sounded like something was … boiling.

Frowning, Nova slowly turned around.

A cloud of steam was drifting up from the shelf where she’d left her experiment.

Her pulse skipped. “What now?” she murmured, abandoning the cart. The sound of bubbling got louder. The steam grew thicker. The air stung her throat with the tang of chemicals.

Nearing the plastic vat, she saw that the electrolyte solution was boiling—great, rolling bubbles popping at the surface and splattering the sides.

“How is that even—”

It exploded.

Nova gasped, jumping backward as the solution splattered everywhere, coating the underside of the next shelf. It flowed over the edges of the bin and splashed across the floor. One of the conductor cables snapped off the battery and was flung from the cell, nearly taking out Nova’s eye before it crashed into the wall.

With the circuit severed, what was left of the liquid quieted to a simmer and soon became still, but for the last dregs still dripping down the sides.

The chromium box sat unaffected, looking infuriatingly innocent inside the bin.

Nova gawked at the mess of chemicals. Her destroyed battery. The wheel that she had scrubbed for a solid hour to make sure it was clean enough for the chromium atoms to adhere to.

A guttural scream tore from her mouth. She grabbed the nearest thing in reach—a gemstone-encrusted brooch—and flung it down the aisle. When it struck the concrete floor, it emitted a blinding white flash. Nova threw her arms in front of her face and stumbled back, but the light disappeared as fast as it had come and the brooch clacked and skittered a few more feet. As the ghost of the flash faded from Nova’s vision, the brooch appeared, luckily, unharmed.

“Okay,” she said, rubbing her eyelids. “I probably shouldn’t have done that.”

“McLain?”

She jumped and spun in a full circle before realizing that the stern voice had been coming from her wristband.

Gulping, she lifted her hand. “Uh … yes?”

“This is Recoil in security. We just saw what appeared to be a small explosion there in the artifacts department. Is everything all right?”

Nova willed her nerve to stop trembling. “Uh—yeah. Sorry. Everything’s fine. I was just”—she cleared her throat—“cleaning a few of the objects here, and, um … must have mis-measured the … cleaning … solution. Sorry to worry you.”

“Would you like us to send down a cleaning crew?”

“No,” she said, adding a lighthearted laugh. “No, no. I’ll take care of it. You know the things in here can be … temperamental. I think it’s best if I handle it.”

“You’re sure?”

“Positive.”

The communication faded out, and Nova inspected the results of her failed—oh, so very failed—experiment.

She ran her hands through her hair and cursed.

So much for science and persistence.

Shoulders slumped, she picked up the brooch and set it gently back in its place, then went off to find a mop.

CHAPTER TWENTY-FOUR

ADRIAN’S CHEST ACHED from his newest tattoo, still sore from a thousand tiny pricks of the needle. Of all his tattoos, this had been the easiest to persuade himself to go through with. He’d known he would do it the moment the Vitality Charm had successfully admitted him into Max’s presence.

The charm worked, and this tattoo would too. After this, he would be able to come and go from the quarantine as he pleased.

With so much importance resting on this design, he had not simply copied the symbol onto his skin. He had spent hours poring through dictionaries, encyclopedias, and tomes on symbolism and ancient healing practices. The symbols that the blacksmith had long ago stamped into the medallion were found across multiple religions and cultures, often carrying messages of protection and health.

The open right hand was said to be a ward against evil, and snakes had been associated with healing and medicine for eons. The more he read, the more he understood how this design could protect someone from forces that would seek to weaken him or her.

Protection. Health. Strength.

The words came up again and again in his research, and had repeated like a mantra in Adrian’s mind as he’d worked on the tattoo.

A serpent curled inside the palm of an open hand.

The hand held up in defiance—Stop. You may not pass.

The serpent, ready to devour any affliction that dared to ignore the hand’s warning.

Together—immunity.

The tattoo, inked directly over his heart, would work. Adrian had already accomplished remarkable things by inking new designs into his skin. He had stretched the limits of his power beyond anything he would have previously thought possible. He had made himself into the Sentinel, and the scope of his abilities seemed endless, limited only by his imagination.

So who was to say that he couldn’t give himself this ability too? Not complete invincibility, like the Captain had. The only way he could think to accomplish that would have been with a tattoo that spanned the full length of his body, and he wasn’t ready for that sort of commitment.

But invincibility from Max? It could be done. It was possible. He had never been so sure of anything in his life.

He went to the mirror to inspect his work. The design looked good. Clean and sharp. Despite having had to work upside down on himself, he was pleased to see how balanced he’d gotten the overall shape. It had turned out exactly how he’d envisioned. A perfect replica of the symbol on the Vitality Charm.

Relaxing his shoulders, Adrian pressed his palm over the tattoo and let his power seep into his body. He felt the same warm, stinging sensation he had every time he did this, as the design sank through his skin and into his muscles, through his ribcage, into his steadily beating heart. As it became a part of him.

When he pulled his hand away, the ink was glowing orange, like melted gold inlaid on his skin. But it faded fast, leaving only the tattoo behind, no different than it had been when he first pulled off the bandage. Unlike his other drawings, the tattoos didn’t disappear after he willed them into reality. Maybe because they were intended to be permanent. Maybe because he wasn’t creating a physical manifestation of the drawing, but rather, using it to change himself.

Adrian was as confident in his tattoos and his new abilities as he’d ever been about anything. As he put away his tattooing kit, he found himself wishing that he could have been even half as sure about Nova and the mixed signals she’d been sending lately.

He was sure … well, pretty sure … a solid 83% sure that Nova had been flirting with him in the training hall. And at the park too. A dozen small moments kept flashing through his memory. A smile that was a bit too bright. Eyes lingering on his a second too long. The way she sat just a little closer to him than she had to. The way her fingers brushed against his back when she’d been teaching him how to shoot.

That was flirting. Wasn’t it?

And flirting meant interest. Didn’t it?

But then he remembered the carnival, and how she had pulled away so hastily when he’d tried to kiss her, and how everything had been awkward between them since, and he figured he had to be imagining things.

The biggest problem was that their time at the carnival had made Adrian painfully aware of how much he had started to like Nova.

Really like her.

He liked how brave she was—that dauntless courage she’d had when she faced off against Gargoyle at the trials. The lack of hesitation to chase after Hawthorn or take out the Detonator. The bravery that veered just a bit toward recklessness. Sometimes he wished he could be more like her, always so confident in her own motivations that she didn’t mind bending the rules from time to time. That’s how Adrian felt when he was the Sentinel. His conviction that he knew what was right gave him the courage to act, even when he would have hesitated as Adrian or Sketch. But Nova never hesitated. Her compass never seemed to falter.