Here's the synopsis again (BEWARE : not spoiler free for those who haven't read Mistborn) :
Three hundred years after the events of the Mistborn trilogy, Scadrial is on the verge of modernity, with railroads to supplement the canals, electric lighting in the streets and the homes of the wealthy, and the first steel-framed skyscrapers racing for the clouds.And a brief taste of the prologue and chapter one :
Kelsier, Vin, Elend, Sazed, Spook, and the rest are now part of history—or religion. Yet even as science and technology are reaching new heights, the old magics of Allomancy and Feruchemy continue to play a role in this reborn world. Out in the frontier lands known as the Roughs, they are crucial tools for the brave men and women attempting to establish order and justice.
One such is Waxillium Ladrian, a rare Twinborn who can Push on metals with his Allomancy and use Feruchemy to become lighter or heavier at will. After twenty years in the Roughs, Wax has been forced by family tragedy to return to the metropolis of Elendel. Now he must reluctantly put away his guns and assume the duties and dignity incumbent upon the head of a noble house. Or so he thinks, until he learns the hard way that the mansions and elegant tree-lined streets of the city can be even more dangerous than the dusty plains of the Roughs.
Wax crept along the ragged fence in a crouch, his boots scraping the dry ground. He held his Sterrion 36 up by his head, the long, silvery barrel dusted with red clay. The revolver was nothing fancy to look at, though the six-shot cylinder was machined with such care in the steel-alloy frame that there was no play in its movement. There was no gleam to the metal or exotic material on the grip. But it fit his hand like it was meant to be there.
The waist-high fence was flimsy, the wood grayed with time, held together with fraying lengths of rope. It smelled of age. Even the worms had given up on this wood long ago.
Wax peeked up over the knotted boards, scanning the empty town. Blue lines hovered in his vision, extending from his chest to point at nearby sources of metal, a result of his Allomancy. Burning steel did that; it let him see the location of sources of metal, then Push against them if he wanted. His weight against the weight of the item. If it was heavier, he was pushed back. If he was heavier, it was pushed forward.
In this case, however, he didn’t Push. He just watched the lines to see if any of the metal was moving. None of it was. Nails holding together buildings, spent shell casings lying scattered in the dust, or horseshoes piled at the silent smithy—all were as motionless as the old hand pump planted in the ground to his right.