There was commotion in Roaring Camp.
The opening line sets the stage for the wholesale upheaval to come. After first letting the reader know the mining camp is all abuzz about something, the narrator provides some context: fights no longer have the power to make a commotion and the name that keeps popping up among whispered voices the most is that of the only woman in the camp; a woman of questionable repute named Cherokee Sal.
The camp lay in a triangular valley between two hills and a river. The only outlet was a steep trail over the summit of a hill that faced the cabin, now illuminated by the rising moon.
The setting of the story is here outlined with subtle attention paid to its geographical peculiarities defining its isolation. The beneficiary of topographical defense against unwanted encroachment all but one direction and that path being allowing access from that direction being difficult as well, the very thing which serves to protect its independence is also at all times invested with the potential for malevolence. Under the right conditions, the inhabitants of Roaring Camp become sitting ducks.
As Kentuck bent over the candle-box half curiously, the child turned, and, in a spasm of pain, caught at his groping finger, and held it fast for a moment. Kentuck looked foolish and embarrassed. Something like a blush tried to assert itself in his weather-beaten cheek.
The commotion turns out to be, of course, the birth of a child to the prostitute who dies shortly after labor. The miners all converge upon the infant to unofficially take on the collective role of father since there is no way at present to tell which of them can actually lay claim to this title. After establishing that the miners are tough outcasts—though perhaps not as tough as they might look—everything changes. This is especially true for the fella they call Kentuck. In this moment of intimacy familiar to nearly everyone who has ever been in the presence of a newborn, something significant changes. Especially for Kentuck, but equally so for the entire camp.
“…we're here for a christening, and we'll have it. I proclaim you Thomas Luck, according to the laws of the United States and the State of California, so help me God."
Here is the quote which explains the title of the story—to a point. Since the paternity of the father cannot be established yet, he is christened with name Luck and, indeed, his presence in in the camp proceeds to bring about a fortunate change among the miners of Roaring Camp. Where once they were lost in the isolated world of between the hills and the river, with the arrival of this blessed child they become found again. The religious overtones to the story are not, by the way, incidental.
Such was the golden summer of Roaring Camp. They were "flush times," and the luck was with them. The claims had yielded enormously. The camp was jealous of its privileges and looked suspiciously on strangers. No encouragement was given to immigration, and, to make their seclusion more perfect, the land on either side of the mountain wall that surrounded the camp they duly preempted. This, and a reputation for singular proficiency with the revolver, kept the reserve of Roaring Camp inviolate.
Yes, indeed, little Tommy seems to truly prove himself worth of his name. The miners invest him with totemic power as they fervently associate the striking reversal of fortune in the mines with the arrival of the baby. Things are good and made even better through the camp being the beneficiary of that topographical defense. But fortune always changes, luck always runs out and it is important to remember that the very thing which benefits them most of the time is subject to becoming the instrument of their doom under just the right circumstances.