An apostle of the private mercenary interest as an organizing principle of behavior, Sol Star is a natural entrepreneur and one of the town's new fathers. He is also the life-long friend of Seth Bullock, and perhaps the only person Bullock confides in.
It was Star who urged Seth Bullock to head out to the new camp in Deadwood. As Bullock's partner in the hardware business, Sol handles most of the financial responsibilities of the endeavor, and his enthusiasm and vigor complement perfectly Bullock's decorum and self-possession.
Sol's good sense is tested with his infatuation with Trixie, Al Swearengen's favorite whore. Speaking his feelings at the Gem, Sol is initially rejected by her. Eventually, however, a visit to the store leads to an offer of "a free f*ck." When Bullock happens onto the couple and accidentally mentions the assignation to Swearengen, a hurt and outraged Al demands payment from Star, who complies.