Kelsier burned iron, flaring it strong and searching the night for large sources of metal. He was too far away from the keep to use small items like coins or hinges. He’d need a larger anchor to cover this distance.
Most of the blue lines were faint. Kelsier marked a couple of them moving in a slow pattern up ahead—probably a pair of guards standing on the rooftop. Kelsier would be sensing their breastplates and weapons. Despite Allomantic considerations, most noblemen still armed their soldiers with metal. Mistings who could Push or Pull metals were uncommon, and full Mistborn were even more so. Many lords thought it impractical to leave one’s soldiers and guards relatively defenseless in order to counter such a small segment of the population.