Moving at a dead run through an unfamiliar city, Alex Sennefer risked a quick look behind him. Were the guards from the museum still after them? Had the police joined the chase? At first, all he saw was a broad street and wide sidewalks, lit at even intervals by streetlights and dotted with nighttime walkers. Then he heard a shout, sharp and clear: “Halt!” A guard rounded a corner and came into view, his tie flapping as his shoes slapped the sidewalk.

Is he armed? wondered Alex. Are there half a dozen more men right behind him? He turned to his best friend, Renata Duran, who was running beside him. “We need to get off this” — he huffed in another breath — “street” — puffed it out — “and hide!”

“Yeah!” said Ren. She was twelve years old, like Alex, but small for her age, and her short legs pumped furiously to keep up. “Which way?”

To their left was a large, dark park, a slumbering stretch of trimmed grass and thick trees, surrounded by a tall iron fence. Alex scanned the fence line for an opening but then thought better of it. A fence could protect them — but it could also trap them inside.

Across the street to the right was a long stretch of open sidewalk and closed shops.

“Go right!” Alex said.

“Okay,” said Ren, “but not yet …”

Alex looked back — now a second guard was running just behind the first.

“Uh, are you sure?” said Alex.

“Wait!” Ren called.

“Why?” he asked. Then he noticed a vague rumbling noise.

“Just keep running!”

Alex swung his head around and saw a single, large headlight in the center of the street. Steel tracks in the road caught the growing light. It was a streetcar, heading toward them.

“Got it!” he shouted. The two friends sprinted off the sidewalk and into the street, straight toward the oncoming train.

The streetcar sounded its horn: a harsh, electric blare.

The guards were closer now and called out in German again: “Halt! Vorsicht!”

But Alex barely heard them as he sprinted across the deadly steel tracks right behind Ren. The horn blared, voices cried out, and the massive car rumbled forward. If he tripped, he’d be cut in half by heavy steel wheels. But with a few quick, careful strides, he and Ren cleared the tracks.

The streetcar rumbled on. Through the windows, Alex could see its few passengers gaping at the brazen duo.

By the time it passed, the two friends were gone. The street was quiet once more, and the guards were bent over, hands on knees, breathing heavily and staring into several small, dark side streets. The trespassers were headed down one of them. They just didn’t know which one.

“I think we lost them,” said Ren as the pair hustled down a short street called Robert Stolz Platz. The street ended in a small park, this one unfenced, and the friends skirted its dark edges.

“Great,” said Alex, taking a quick look back and slowing his pace. “Then it’s official: We’re all lost.”

They took a left onto a street bearing the improbable name Nibelungengasse and slowed to a walk. “Yeah,” said Ren, breathing heavily and looking both ways down the little street. “Seriously. Where are we?”

He knew she didn’t mean what street or even what neighborhood. She meant what city? What country? They had arrived here through a false door, a ceremonial ancient Egyptian portal that had somehow allowed them to travel from the Valley of the Kings in Egypt to another false door in the Egyptian wing of a museum here — wherever here was.

For weeks, Alex and Ren had been on the hunt for two things: Alex’s mom and the powerful Lost Spells of the Egyptian Book of the Dead. His mom had used those Spells to revive him as he lay on life support in a New York hospital. But in doing so, she’d opened a gateway to the afterlife and the sinister ancient entities known as the Death Walkers had escaped. She and the Spells vanished after that, and Alex and Ren had traveled halfway around the world to find them.

But they weren’t the only ones. The Order’s deadly operatives were looking for them, too, and hounded the friends wherever they went. They knew the evil cult was working with the Death Walkers in some vast sinister conspiracy. The last Walker had spoken of ruling with The Order. Whatever they were up to, it was big, and if the cult found the Spells first, the Death Walkers would be unstoppable, and the whole world would suffer.

Alex shuddered slightly in the night and looked around at a scene that seemed far less grim. The buildings were lit softly by a combination of streetlights and moonlight, and the architecture was old and beautiful. “It’s so pretty,” said Ren.

“This whole city looks like something you’d find on top of a cake,” agreed Alex. He nodded toward a nearby building. It was painted a delicate light green that did, indeed, look a bit like frosting. It reminded him of an exhibit he’d seen at The Metropolitan Museum of Art back in New York, where his mom had worked as an Egyptologist before she disappeared. “Is that, like, art deco?” he said.

Ren shook her head in disapproval. “Don’t be ignorant,” she said. “It’s art nouveau.”

“Oh, obviously,” he said sarcastically, but he didn’t doubt her. He was aware that she knew a lot more about it than he did. Her dad was a senior engineer back at the Met, his mom’s most trusted coworker, and Ren had inherited his love of elegant angles and solid construction.

“What was that?” Ren gasped, interrupting his thoughts.

“What was what?”

“I thought I saw something slip between those buildings,” said Ren, pointing. “Just, like, a shadow.”

Alex followed her finger but didn’t see anything. “It’s the middle of the night,” he said. “There are shadows everywhere.”

New voices echoed down the little street. A small white dog turned the corner and then two people appeared behind it. “Let’s ask them where we are,” said Alex.

“Can we trust them?” said Ren.

Alex understood her cautiousness. They had already been betrayed once that night. He could still picture his cousin Luke standing up in the moonlit desert and shouting, Over here, giving away their position to the brutal death cult. He was still stunned that his own cousin was working for The Order … but another glance at the middle-aged couple put his mind at ease. “They’ve got a shih tzu,” he said. “Not exactly an attack dog.”

He waved as the couple approached: a man and a woman, wearing casual clothes but fancy shoes. The signs — and shouts — had all been in German so far, but that was the only clue they had about their location. Fortunately, his mom’s family was from Germany.

“Hallo!” he called. He knew that part. “Wo, um, sind wir?” Where are we? Maybe? He was less sure of that, and longed for the smooth, fluid German his mom had always used on the phone with his grandmother.

The man holding the leash smiled and responded with a barrage of rapid-fire German that baffled Alex.

“Ich spreche nur ein bisschen Deutsch,” said Alex with an apologetic shrug. I speak only a little German.

The woman answered this time, wearing a patient smile and speaking precise English. “You are American, yes? You are on Nibelungengasse.”

Ren spoke up. “Not what street,” she said. “We’d like to know what city this is.”

The dog walkers exchanged quick, confused smiles. Even the dog seemed to regard them with tongue-lolling pity.

“You are in Wien, of course,” said the man. “Vienna. Is there something you need help with? Are you … lost?”

“No, we’re fine,” said Alex. “But thanks.”

The dog walkers went on their way, but the strangest thing happened as Alex turned to give one last embarrassed wave. He thought he saw a shadow, too, a thin slice of night slipping from one side of the streetlight’s glow to the other.

“Wow, Vienna,” said Ren, looking around with fresh eyes.

“That’s got to be two thousand miles from where we were,” said Alex. “And it felt like it took a minute.” He remembered their desperate sprint through a strange and murky landscape … Had they really traveled through the afterlife?

His mind was full of big questions and confusing new realities, but right now he had a more immediate concern. As his eyes scanned the dark edges of the street, he felt the ancient scarab amulet at his neck growing warm against his skin. A warning: Death was lurking nearby.

“Maybe we should, uh, find someplace to stay,” he said.

He suddenly wanted to be anywhere other than the dark streets of an unfamiliar city. He reached into the pocket of his jeans, but all he pulled out was a handful of Egyptian bills. Useless. What good was Egyptian capital in the capital of Austria?

“Maybe we can find somewhere to change those when the stores open tomorrow,” said Ren.

“Maybe tomorrow,” Alex repeated absently. His eyes were fixed on a dark corner that seemed, somehow, to be darker than the rest.

It was tonight he was worried about.