Rathbone had no argument, except that there must be something more, some evidence undiscovered so far that would change the entire picture.

“I’m sorry,” Monk added. “I’ll go on investigating it, but largely to find the links between them and to destroy the trade. I wish the trail hadn’t led to Ballinger, but it did. If you can get him to confess, it might at least spare his family some of the shame.”

Rathbone felt bruised, stunned, as if he had taken a heavy blow and it had left him dizzy. “There has to be another answer.”

“I hope so.” Monk smiled bleakly. “It would be very nice to think it could be someone neither of us cares a damn about. But wishing doesn’t make it so.”

Rathbone could think of nothing more to say. He thanked Monk and excused himself.

He was in the outside office on his way to the dockside again when he almost bumped into a tall, thin man with white side whiskers and intense blue eyes. He was dressed in an expensive and very well-cut suit. Rathbone knew him by sight, and on this occasion would have avoided him if he could have.

“Morning, Commander Birkenshaw,” he said briefly, and continued walking.

But Birkenshaw was not to be avoided. He came across the few yards between them and followed Rathbone outside into the brisk, fresh air on the dock.

“Thought you’d be here early,” he said, matching his stride to Rathbone’s. “Wretched business. I was hoping we could get it all untangled before it comes to anything. You’ve known Monk for many years, haven’t you?”

“Yes. Eight or nine, I think,” Rathbone replied reluctantly.

Birkenshaw was Monk’s superior, and he was clearly very unhappy. His face was pinched with anxiety, and he kept his voice low, even though there was no one within earshot in the bright, sharp morning. The noise of the wind and water would have made overhearing unlikely anyway.

“Would you say you know him well?”

There was no evading an answer. “Yes. We’ve worked together on many cases.”

“Clever,” Birkenshaw conceded. “But reliable? I know Durban thought highly of him. He recommended him for the post when he knew he himself was dying. But he hadn’t known Monk all that long; just the one case. I’ve heard from others since then that Monk’s a bit erratic. Farnham, my predecessor, was uncertain as to his integrity, if it came to a difficult decision and Monk was personally convinced of someone’s guilt.”

“Then, it’s as well that you are now in command, and not Farnham,” Rathbone said tartly, and immediately regretted it. He saw the surprise in Birkenshaw’s face, and then the irritation. It was not the answer he had been seeking.