Eve Forward said this quote

“ But see you, we should travel by night. Dark times for dark business, as they says. No sun to bother Valeriana or you, Kaylana's surely no' disadvantaged, and I know I work better in darkness. Anybody looking for us will have a harder time of it. Besides, marching in daylight is for the heroes. If we're going to do this, we may as well go all out. ”