OLIVIA PROCEEDED WITHOUT incident to a freeway on-ramp. They drove north through a sparse industrial zone that led into the southern outskirts of downtown Seattle. There they joined with I-5, the main north-south freeway, which they took all the way through the city. Half an hour later, after they had passed through another belt of suburbs and entered another, smaller city, she flicked on her turn signal and exited onto an east-going highway of lesser importance that proceeded across an endless series of tidal sloughs on long straight causeways. A range of mountains erupted from the flatlands directly ahead of them. Once it had gotten up onto slightly higher and drier land, the highway diverted south and began to wind to and fro, as if unnerved by the colossal barrier stretched across its path, but after a while it got funneled into a broad valley, clotted with small communities. The valley became narrower, the air colder, the towns smaller, the trees taller, and then it was clear that they were ascending into a mountain pass.