Cohen sat in the passenger seat of Lopez’s Audi and stared out at the buildings passing by in the bright morning sunshine. He’d yet to shake his fish-out-of-water discomfort at having stepped from a criminal investigation into a public-health probe. But he appreciated that both had the same ultimate endpoint: finding Dennis Tyler and the people behind him. He had never lost sight of his quest to find Carol Wilson’s killer.

Cohen appreciated the way Lopez and Kilburn took the time to explain the technical jargon without patronizing. He enjoyed their company, too, but he couldn’t ignore the chemistry he sensed between Kilburn and Lopez. That, not his jog, was what had actually kept him from joining them at breakfast. Cohen had no desire to be a third wheel. And the more time he spent around Lina, the more difficulty he had focusing on the job. Latina good looks aside, her rocket ship personality wowed him more than anyone had in a long time.

“What are you thinking about?” Lopez asked, adjusting her sunglasses.

“Medicine,” Cohen said obliquely.

“You looking for a career change?”

“Not when the job is even more depressing than Homicide,” he said with a slight grin. “I was thinking, though, that there are more similarities between our jobs than I’d have ever guessed.”

“Absolutely.” She nodded. “Particularly what I do. Epidemiology is all about following the broken trail of evidence back to a source. In fact, during my fellowship I had to take a few criminology courses on the principles of police investigation. I loved them.”

“So maybe you’ll be the one switching jobs?” Cohen suggested with a smile.

“Never.” She brushed back a few strands of hair that had drifted over her forehead. “I love what you do except for the criminals themselves. I’d rather deal with homicidal bugs than homicidal people any day.”

“Lina, I think right now you’re dealing with both.”

“Yeah, I guess,” she murmured. “So how did you wind up as a cop?”

Cohen chuckled. “That’s what my dad always asks.” Lopez flashed a toothy smile. “He’s not proud of his detective son?”

“Not outwardly.” Cohen said, thinking of his father’s tendency to substitute wit for affection. “He calls me the Jewish Charlie Chan. Claims he doesn’t have a clue why I do it.”

“Why do you?”

He cleared his throat, uncomfortable at being the subject of conversation. “My partner jokes that I have an overdeveloped sense of revenge.”

Lopez frowned without taking her eyes off the road. “Any truth to that?”

“I guess I like the balance,” he said with an awkward laugh. “Someone breaks the law. I help bring him or her to justice. And it’s all a wash … theoretically.”

“Okay.” She sounded unconvinced.