Character Analysis
Emery Staines begins the novel associated with the moon and ends up as the sun (which is when Anna takes over as the moon).
As you already know from reading Anna's character summary, the character occupying the "sun" position is pretty much in the spotlight (or sunlight?) at the center of all the action, and that's where Anna spends the first 700+ pages of the novel. However, all that changes for the last 100ish pages, when Emery comes out of hiding and the novel shifts focus to exploring whom he is, where he's been, and what he's been doing.
The first thing to know about Emery is that he's really, really young. In fact, he and Anna are the same age, but he's definitely painted as more innocent, ingenuous, and naïve. Might have something to do with the fact that, unlike Anna, he hadn't been tricked into entering prostitution—we imagine that might age a person pretty quick. Anyway, when Devlin meets Staines, he judges him to be "a sweet-natured, credulous lad, ready with a smile, and full of naïve affection for the foibles of the world around him" (IV.2.8).
Of course, that naiveté and credulousness soon drive Devlin crazy when he's helping Staines get ready for his trial. You see, Staines ends up on trial for a variety of things, including cheating Quee Long out of the Aurora's "earnings" when he hid the money Quee had smelted and banked under the name of that claim. It's important to note that Staines didn't really cheat Quee on purpose—he simply didn't think about him in his zeal to stick it to Frank Carver.
Anyway, back to our point: when Devlin is helping Emery prepare for the trial, he gets frustrated by the kid's "foolishness" and apparent unwillingness to take what is happening to him and Anna seriously:
I fear that he does not really understand the gravity of the situation at hand. He has a sweet temper, but in his opinions he tends toward foolishness. When I raised the issue of Miss Wetherell's lunacy, for example, he was perfectly delighted by the idea. He said he wouldn't have her any other way. (IV.2.52)
Emery seems to maintain that kind of irrepressible joyfulness throughout the story:
He was delighted by things of an improbably or impractical nature, which he sought out with the open-hearted gladness of a child at play. When he spoke, he did so originally, and with an idealistic agony that was enough to make all but the most rigid of his critics smile; when he was silent, one had the sense, watching him, that his imagination was nevertheless usefully occupied, for he often sighed, or nodded, as though in agreement with an interlocutor whom no one else could see. (V.2.7)
While Devlin might have found Emery's levity frustrating at times, it's hard not to find it endearing, don't you think? And his positive attitude is probably pretty handy when Emery is sentenced to nine years of hard labor, after which he'll have to rebuild his fortune more or less from scratch.