She landed on a rooftop, jarring to a sudden halt as she grabbed hold of the building's stone lip, leaning out over a street three stories below. She maintained her balance, mist swirling below her. All was silent.

Well, that didn't take long, she thought. I'll just have to explain to Elend that—

OreSeur's canine form thumped to the rooftop a short distance away. He padded over to her, then sat down on his haunches, waiting expectantly.

Vin frowned. She'd traveled for a good ten minutes, running over rooftops with the speed of a Mistborn. "How. . .how did you get up here?" she demanded.

"I jumped atop a shorter building, then used it to reach these tenements, Mistress," OreSeur said. "Then I followed you along the rooftops. They are placed so closely together that it was not difficult to jump from one to another."

Vin's confusion must have shown, for OreSeur continued. "I may have been. . .hasty in my judgment of these bones, Mistress. They certainly do have an impressive sense of smell—in fact, all of their senses are quite keen. It was surprisingly easy to track you, even in the darkness."

"I. . .see," Vin said. "Well, that's good."

"Might I ask, Mistress, the purpose of that chase?"

Vin shrugged. "I do this sort of thing every night."

"It seemed like you were particularly intent on losing me. It will be very difficult to protect you if you don't let me stay near you."

"Protect me?" Vin asked. "You can't even fight."

"The Contract forbids me from killing a human," OreSeur said. "I could, however, go for help should you need it."

Or throw me a bit of atium in a moment of danger, Vin admitted. He's right—he could be useful. Why am I so determined to leave him behind?

She glanced over at OreSeur, who sat patiently, his chest puffing from exertion. She hadn't realized that kandra even needed to breathe.

He ate Kelsier.

"Come on," Vin said. She jumped from the building, Pushing herself off a coin. She didn't pause to see if OreSeur followed.

As she fell, she reached for another coin, but decided not to use it. She Pushed against a passing window bracket instead. Like most Mistborn, she often used clips—the smallest denomination of coin—to jump. It was very convenient that the economy supplied a prepackaged bit of metal of an ideal size and weight for jumping and shooting. To most Mistborn, the cost of a thrown clip—or even a bag of them—was negligible.

But Vin was not most Mistborn. In her younger years, a handful of clips would have seemed an amazing treasure. That much money could have meant food for weeks, if she scrimped. It also could have meant pain—even death—if the other thieves had discovered that she'd obtained such a fortune.

It had been a long time since she'd gone hungry. Though she still kept a pack of dried foods in her quarters, she did so more out of habit than anxiety. She honestly wasn't sure what she thought of the changes within her. It was nice not to have to worry about basic necessities—and yet, those worries had been replaced by ones far more daunting. Worries involving the future of an entire nation.

The future of. . .a people. She landed on the city wall—a structure much higher, and much better fortified, than the small wall around Keep Venture. She hopped up on the battlements, fingers seeking a hold on one of the merlons as she leaned over the edge of the wall, looking out over the army's fires.

She had never met Straff Venture, but she had heard enough from Elend to be worried.

She sighed, pushing back off the battlement and hopping onto the wall walk. Then she leaned back against one of the merlons. To the side, OreSeur trotted up the wall steps and approached. Once again, he went down onto his haunches, watching patiently.

For better or for worse, Vin's simple life of starvation and beatings was gone. Elend's fledgling kingdom was in serious danger, and she'd burned away the last of his atium trying to keep herself alive. She'd left him exposed—not just to armies, but to any Mistborn assassin who tried to kill him.

An assassin like the Watcher, perhaps? The mysterious figure who had interfered in her fight against Cett's Mistborn. What did he want? Why did he watch her, rather than Elend?

Vin sighed, reaching into her coin pouch and pulling out her bar of duralumin. She still had the reserve of it within her, the bit she'd swallowed earlier.

For centuries, it had been assumed that there were only ten Allomantic metals: the four base metals and their alloys, plus atium and gold. Yet, Allomantic metals always came in pairs—a base metal and an alloy. It had always bothered Vin that atium and gold were considered a pair, when neither was an alloy of the other. In the end, it had turned out that they weren't actually paired; they each had an alloy. One of these—malatium, the so-called Eleventh Metal—had eventually given Vin the clue she'd needed to defeat the Lord Ruler.

Somehow Kelsier had found out about malatium. Sazed still hadn't been able to trace the "legends" that Kelsier had supposedly uncovered teaching of the Eleventh Metal and its power to defeat the Lord Ruler.

Vin rubbed her finger on the slick surface of the duralumin bar. When Vin had last seen Sazed, he'd seemed frustrated—or, at least, as frustrated as Sazed ever grew—that he couldn't find even hints regarding Kelsier's supposed legends. Though Sazed claimed he'd left Luthadel to teach the people of the Final Empire—as was his duty as a Keeper—Vin hadn't missed the fact that Sazed had gone south. The direction in which Kelsier claimed to have discovered the Eleventh Metal.

Are there rumors about this metal, too? Vin wondered, rubbing the duralumin. Ones that might tell me what it does?

Each of the other metals produced an immediate, visible effect; only copper, with its ability to create a cloud that masked an Allomancer's powers from others, didn't have an obvious sensory clue to its purpose. Perhaps duralumin was similar. Could its effect be noticed only by another Allomancer, one trying to use his or her powers on Vin? It was the opposite of aluminum, which made metals disappear. Did that mean duralumin would make other metals last longer?

Movement.

Vin just barely caught the hint of shadowed motion. At first, a primal bit of terror rose in her: Was it the misty form, the ghost in the darkness she had seen the night before?

You were just seeing things, she told herself forcefully. You were too tired. And, in truth, the glimmer of motion proved too dark—too real—to be the same ghostly image.

It was him.

He stood atop one of the watchtowers—not crouching, not even bothering to hide. Was he arrogant or foolish, this unknown Mistborn? Vin smiled, her apprehension turning to excitement. She prepared her metals, checking her reserves. Everything was ready.

Tonight I catch you, my friend.

Vin spun, throwing out a spray of coins. Either the Mistborn knew he'd been spotted, or he was ready for an attack, for he easily dodged. OreSeur hopped to his feet, spinning, and Vin whipped her belt free, dropping her metals.

"Follow if you can," she whispered to the kandra, then sprang into the darkness after her prey.

The Watcher shot away, bounding through the night. Vin had little experience chasing another Mistborn; her only real chance to practice had come during Kelsier's training sessions. She soon found herself struggling to keep up with the Watcher, and she felt a stab of guilt for what she had done to OreSeur earlier. She was learning firsthand how difficult it was to follow a determined Mistborn through the mists. And she didn't have the advantage of a dog's sense of smell.

She did, however, have tin. It made the night clearer and enhanced her hearing. With it, she managed to follow the Watcher as he moved toward the center of the city. Eventually, he let himself drop down toward one of the central fountain squares. Vin fell as well, hitting the slick cobblestones with a flare of pewter, then dodging to the side as he threw out a handful of coins.