Title: The Grave Shift

The term Graveyard Shift is usually applied to the very late-night to early-morning shift (contrasted with the Day Shift and the Swing Shift), in most professions because it's "extremely dead".

Given the natural state of the night-life in Vegas, however, and because it would thus be the one to pick up most cases that occur in the active hours of Vegas, it's the most important one, and the one Grissom and company generally were supposed to be working on (Eckley handles Day Shift and Catherine was, at one point, the Swing Shift supervisor). Mind you, there's been only limited evidence of this -- they are often doing things in broad daylight, including taking on new cases, without much explanation).