Sentence:  "Why doubt his guilt?" / Wolfe's shoulders went up a fraction of an inch, and down again. "Divination. Contrariety." / "I see." Unger pursed his midget mouth, which didn't need pursing. "You're shooting at it <WSD>on spec</WSD>." 
Meaning of the word marked with <WSD> tags:  With the hope of selling it, as opposed to on commission (for hire).