TWO DAYS LATER SHE WAS IN THE CITY OF GUANAJUATO, STATE of Guanajuato. The city was built on the slopes of opposing hills. It was beautiful. Not just another place, Luz felt, but one to really look at. Impressive cathedrals. Old musicians played guitars on corners where the streets bent and turned at ridiculous angles and couldn’t accommodate vehicles. She bought a container of sliced mango and wandered, pausing to read the signs denoting the city’s history. She stopped at the hulking square Alhóndiga, and considered the corner once festooned with the head of a man also named Hidalgo. She followed a hiking trail out of town to an abandoned antique mine. This city had been Spain’s cradle of silver. The entrance to the mine gaped in the ground. A guide with a group of Canadian tourists offered to take her a kilometer down the lightless column for only twenty pesos, but she refused the offer. What she wished for was the knife; she wished she could hurl it back, send it clattering down the mine shaft to the place of its birth as though this might undo something. Fall, slashing, to sever the knot where all borders are anchored.