A/N: This is a crossover I've been working on for quite a while, and I'm excited to finally share it! A few notes before you get started reading: This takes place in an "Everybody Lives" alternate ending to Ptolemy's Gate, meaning that Nathaniel survived the battle with Nouda. It's been a few years since then, so Nathaniel and Kitty are meant to be about 19-21 in this fic. Lockwood & Co. are fresh off the events of The Creeping Shadow when this fic takes place, but haven't been through the events of The Empty Grave. I love trying to combine the worlds of Jonathan Stroud, and I hope you enjoy reading this fic as much as I enjoyed writing it!

Chapter 1

Nathaniel shivered and crossed his arms tightly. His sweater did little to stave off the cold in the government vaults, and he'd been down there for hours.

"Ooh, it does feel a bit nippy in here, doesn't it?"

Nathaniel glanced to his left and found Bartimaeus pretending to shiver along with him, wearing a puffy jacket so big it nearly swallowed up Ptolemy's small frame serving as the djinni's current guise. The magician rolled his eyes, knowing perfectly well Bartimaeus wasn't bothered by this insignificant amount of cold.

Bartimaeus met Nathaniel's gaze and grinned. "Want me to light a fire? It would make the room nice and toasty!"

"Yes, and burn us all up in the process," Kitty snapped from Nathaniel's other side. She was bent over a large wooden box, busying herself with sifting through various items of unknown magical origin. She paused momentarily to glare at the djinni. "With all the documents in this stuffy room, one spark would light the whole place up in seconds."

"No need to get tetchy; it was merely a suggestion!" Bartimaeus responded, sounding offended, making the puffy jacket disappear with a wave of his hand to reveal the jeans and grey t-shirt he'd dubbed his "modern" outfit underneath.

"It was a bad one, and you know it." Kitty went back to rummaging around in the box. "Can either of you make yourselves useful and help me find this stupid thing? Nathaniel, remind me what we're even looking for again?"

"Um, let me check," Nathaniel replied, uncrossing his arms and reaching into his pocket. He pulled out an index card and read, "'A small, rounded grey disc.' Be careful rooting around for it, though; supposedly those who have touched disc have… 'disappeared?'" Nathaniel frowned. "If that's the case, I don't know why they'd leave it at the bottom of a box, lumped in with a bunch of other magical artifacts…"

"Why do humans make any of the decisions that they do?" Bartimaeus mused. He sighed dramatically, shaking his head. "5,000 years coming and going from this dreadful Earth, and I still haven't the faintest idea."

Nathaniel pointedly ignored him, silently reading over the index card again.

Two years after the Makepeace Incident, as the attempted overthrow of the government and subsequent near-takeover by magical spirits had become known, Nathaniel was fully resituated into his job as Information Minister. Once he'd recovered from his miraculous survival, there was talk of him moving up in the ranks, and even mention of him taking on the role of Prime Minister someday. But after everything he'd been through, Nathaniel realized he truly didn't want the immeasurable power that came with leading an entire country. All he wanted was to have a stable job that kept him busy, with his newfound companion Kitty by his side.

Nathaniel never planned to see Bartimaeus again, figuring that after all the djinni had done for him and the world, he deserved a long rest. But, to his surprise, the time they spent bonded together (not to mention Kitty's visit to the Other Place) had sparked a strange desire for Bartimaeus to want companionship from the two of them. Of course, until a way to freely move back and forth from the Other Place was discovered, Bartimaeus could only visit through a Summoning. So, the djinni agreed to be occasionally summoned to Earth by his familiar master under the strict condition that Nathaniel would release Bartimaeus whenever he wished.

This arrangement suited everyone just fine. Nathaniel had to admit that being so closely connected to the djinni's essence created an irrevocable bond between them; he often felt as though a part of him was missing whenever Bartimaeus rested in the Other Place. There were so many things about Bartimaeus and Spirits in general that Nathaniel wanted to learn, and the snarky djinni was more than willing to divulge this information to him and Kitty in his own time. The trio still argued constantly, but their words were now only full of playful banter; a mutual understanding between them assured that no one truly wanted to hurt each other anymore.

It was during one of Bartimaeus' visits that Nathaniel had been tasked to go down to the government vaults and locate an item of interest for Internal Affairs to review. Kitty wanted to help, and her new position in the government, as well as her close relationship with Nathaniel, allowed her to aid him with this task. While Kitty never wanted to be too embroiled in politics, she found success and a sense of worth as the official liaison between the members of Parliament and the common people. Nathaniel had been extremely vocal about Kitty's efforts in helping take down Nouda, giving Kitty a notoriety that allowed her to have a hand in a lot more things than would normally be expected from her job title alone.

Thus, the trio found themselves down in the dusty government vaults. Kitty immediately set to work rifling through boxes upon their arrival and, seeing as she was on a mission, Nathaniel and Bartimaeus knew not to get in her way unless she asked for assistance.

"Wait, I might not need your help after all!" Kitty suddenly exclaimed. With a grunt of effort, she pushed herself back onto her feet. A circular object was clutched in her right hand, barely wider than the length of her palm. It was wrapped in a black cloth that had begun to fall off in one place, revealing an outer edge to the grey disc laced with an intricate pattern.

"Those are runes!" Nathaniel said excitedly, peering closely at the exposed edge. "Like from a summoning circle, but… off, somehow."

"Interesting," Bartimaeus agreed, his golden eyes lighting up with curiosity.

Kitty laid the disc on top of another box and carefully pulled the cloth away, revealing a scrying glass covered in strange markings on the outer circle. The three of them stared at the disc, trying to decipher what it was and, more importantly, what it was usedfor.

"It seems like a combination of runes for a typical summoning, some Ptolemaic markings of a reverse summoning circle, and…" Nathaniel wrinkled his nose in confusion, pointing to a symbol scratched near the edge of the disc. "…something else. I'm not sure what that symbol means. Bartimaeus, care to enlighten us?"

"What, that one?" Bartimaeus raised an eyebrow. "That's the Greek word for 'stay!' Come on, Nat; this is kids' stuff!"

"No, not that one!" Nathaniel jabbed his finger a little closer. "That one!"

"The Egyptian symbol for water?"

"No!"

"The Greek word for-"

"I can read Greek!" Nathaniel let out a growl of frustration. Bartimaeus knew just how to push his buttons, especially when he wasn't in the mood for it. The slightly upward tilt of the djinni's mouth made Nathaniel glare harder. "This symbol right here."

For a second, dead silence filled the room. Nathaniel swiveled between Kitty and Bartimaeus' shocked expressions, eventually casting his gaze downwards to where his index finger pressed firmly against the grey disc. Another beat of silence passed, and then Kitty began to shout.

Nathaniel couldn't hear her words clearly, for his mind was solely focused on his hand currently being pulled into the center of the disc. The rest of his arm followed suit, flattening and twisting as if it were liquid being pulled down a drain. He felt only a numb tingling sensation, and for that he was grateful. If he was about to die, he'd rather it be fast and painless.

A tug on Nathaniel's other hand made him glance back to find Bartimaeus clutched onto him with an iron grip. The djinni pulled as hard as he could, and this did cause Nathaniel much discomfort; he felt as though his arm might be ripped out of its socket. Kitty firmly grasped him around the waist and tried to aid Bartimaeus in moving Nathaniel away from the dangerous object.

But the pull of the disc was far stronger than the combination of a determined human and a powerful spirit. Before he could utter any poignant final words, the rest of Nathaniel's body was sucked into the disc and the world went black around him.

When Nathaniel opened his eyes, his first thought was that the afterlife looked extremely dull. He'd expected white, pearly gates or some other fantastical sight, but the area he laid in was dark, dingy, and only marginally warmer than the government vaults. He felt a pressure upon him and turned his head to see Kitty laying on his back, arms still clamped tightly around his waist. Her eyes were shut, face twisted in an expression of fear and determination.

"Kitty?" Nathaniel said quietly. He made a move to stand and realized that Bartimaeus' hand remained tightly around his own. The magician gave a small sigh of relief; if the djinni was present, it meant that Nathaniel was still alive. It also meant that they weren't completely defenseless.

"It amazes me how you continue to do such stupid things after all this time," Bartimaeus commented dryly, his eyes glowing in the dim light as he wrenched his hand back. His intense glare made Nathaniel grimace; he could tell Bartimaeus was legitimately upset with him.

"I agree, and we need to have a serious talk about that again… but that's not our main concern right now," Kitty said, disentangling herself from Nathaniel. Bartimaeus stood and held out his hands; Nathaniel grabbed one, Kitty took the other, and in one swift motion, the djinni pulled them both to their feet. As the trio examined their surroundings, they realized a rather startling fact:

They were not alone.

A pudgy boy sat at one of the desks that formed a semi-circle around the room. He had round spectacles, wide, bright blue eyes, and a pale-lipped mouth that hung open like a fish. His gaze swiveled to each member of the trio, trying to take them all in at once.

"Oh, uh… hello!" Nathaniel quickly regained his composure, straightening out his shirt and puffing himself up like a person with authority. He flashed a smile, but the boy simply stared. Nathaniel noted that he appeared to be in his mid-teens. The magician took a step forward and extended a hand. "We apologize for the intrusion but… we seem to have found ourselves here accidentally."

"…I can see that," the boy responded, slowly getting to his feet. The trio watched him intently as his eyes flickered to a door at the other end of the room. "And how exactly did you end up here?"

"Well…" Nathaniel trailed off, wondering how much he could reveal. His work within the government vaults was top secret and couldn't be shared with just anyone he came across.

"Magic," Bartimaeus said, and Nathaniel snapped his head towards him. The djinni wore an indecipherable expression, though Nathaniel could tell by his posture—arms crossed, hip jutting out slightly, eyes scanning the boy up and down—that Bartimaeus was sizing this kid up to determine how much of a threat he was.

"…Magic, huh?" The boy looked mildly offended as he removed his glasses and rubbed them furiously on the bottom of his sweatshirt. "Right. Well… I know someone who's quite skilled in magic, so… I'm just going to pop upstairs and find him."

The boy calmly repositioned his glasses onto his nose. Then, with a surprising burst of speed, he suddenly bolted for the door. Kitty took off after him, but the boy was already too far ahead of her and slammed the door in her face. Kitty smacked a fist against it with a growl of frustration, while Nathaniel looked at Bartimaeus questioningly.

"Why didn't you go after him?!" he asked. The djinni shrugged.

"He's just a human," Bartimaeus responded. "Maybe he's getting help, maybe he's getting the authorities. If he causes trouble when he comes back, I'll take care of him. Right now, our most important task is to try to find a way out of here. Since that disc was obviously a portal, I suggest we see if there's a matching one somewhere in this room."

Nathaniel pursed his lips but couldn't argue with Bartimaeus' logic. He glanced at Kitty, who had already busied herself with trying to pick the door lock with a hairpin pulled from one of her jacket pockets. Nathaniel sighed and turned back to Bartimaeus; with a nod, they began their search for a way home.