Mistborn #03 The Hero of Ages

way, then find that the Lord Ruler had been as stumped as they were. And, if he'd known more—as his words implied that he did—why hadn't he shared it on the plate? And yet, she could sense his instability even through these words—his washing back and forth from contrition to arrogance. Perhaps that was Ruin's influence on him. Or, perhaps it was simply the way he had always been. Either way, Vin suspected that the Lord Ruler couldn't have told her much more that would have been of use. He'd done what he could, holding Ruin at bay for a thousand years. It had corrupted him, perhaps even driven him mad.
    That didn't stop her from feeling a sharp sense of disappointment at what the plate contained. The Lord Ruler had been given a thousand years to worry about what would happen to the land if he were killed before the power returned to the Well, and even he hadn't been able to come up with a way out of the problem.
    She looked up toward the plate, though in the darkness, she could not see it.
    There has to be a way! she thought, refusing to accept the Lord Ruler's implication that they were doomed. What was it you wrote at the bottom? "I have hidden his body well."
    That part seemed important. However, she hadn't been—
    A sound rung through the darkness.
    Vin turned immediately, growing tense, feeling for her last metal vial. Proximity to Ruin had made her jumpy, and she found her heart beating with anxiety as she listened to the echoing sounds—sounds of stone grinding against stone.
    The door to the cavern was opening.

One might ask why Ruin couldn't have used Inquisitors to release him from his prison. The answer to this is simple enough, if one understands the workings of power.
    Before the Lord Ruler's death, he maintained too tight a grip on them to let Ruin control them directly. Even after the Lord Ruler's death, however, such a servant of Ruin could never have rescued him. The power in the Well was of Preservation, and an Inquisitor could only have taken it by first removing his Hemalurgic spikes. That, of course, would have killed him.
    Thus, Ruin needed a much more indirect way to achieve his purpose. He needed someone he hadn't tainted too much, but someone he could lead by the nose, carefully manipulating.
    49
    SAZED MADE A SMALL NOTATION ON HIS DIAGRAM, comparing measurements of the waterway. From what he could tell, the Lord Ruler hadn't really needed to do much to create the underground lake. Water had already been flowing into the cavern. The Lord Ruler's engineers had simply widened the passageways, bringing in a steadier, surer flow that outpaced the natural drainage.
    The result was an aquifer of good size. Some machinery in a side cave proved to be a mechanism for plugging the outlets at the bottom—presumably so that one could keep the water reserve from escaping, should something happen to the incoming supply. Unfortunately, there was no existing way to block off the inlets.
    Before the Lord Ruler's creation of the reservoir, only a small amount of the water had passed into the cavern. The rest flowed instead into what were now the streets, filling the canals. So, Sazed assumed, if he could stop the water from entering the cavern, it would refill the canals.
    I'll need to know more about water pressure, Sazed thought, so I can provide enough weight to plug those inlets. He thought he'd seen a book on the subject inside his metalmind.
    He leaned back in his chair, tapping his metalmind. Memory blossomed inside his head as he withdrew a section of text: an index he'd made listing the titles of books he had in his storage. As soon as he pulled the text out, the words became as clear to him as if he'd just read and memorized them. He scanned through the list quickly, seeking the title he needed. When he found it, he scribbled it on a piece of paper. Then, he placed the list back inside his coppermind.
    The experience was odd. After replacing the list, he could recollect having drawn the material out—but, he had no memory whatsoever of what the index had contained. There was a blank in his mind. Only the words scribbled on the paper explained things that he'd known just seconds before. With that title, he could draw the appropriate book into his mind in its entirety. He selected the chapters he wanted, then stuck the rest back into the coppermind, lest they decay.
    And, with those chapters, his knowledge of engineering was as fresh as if he'd just read and studied the book. He easily