"Ah! Another sartorial non-conformist," Phlox greeted the Doctor.
"The subcommander has convinced the captain that I'm as concerned for your missing passenger as they are," explained the Doctor.
"He's not as convinced as he might be," said Reed, the Doctor's security escort.
Phlox didn't care. "Look at this," he said with delight, and showed the Doctor the Suliban's unusual skin features. "And that's only what I've found so far."
The Doctor found the biological advances he and Phlox discovered in the Suliban to be ambiguous as evidence of time-tampering. He knew nothing of the Suliban, who according to Phlox were otherwise run of the mill humanoids. These cover operatives could be a part of the Doctor's history unknown to him, or they could be agents of the unknown adversary. Best just to gather all the data he could. "While I'm here, may I see what you have on the Klingon courier?" Perhaps there was something about him the Doctor could spot that Phlox couldn't.
"Here we go." Phlox brought up visuals and telemetry summaries on a screen.
There was something for the Doctor to spot that Phlox couldn't. "That's a post-Transformation Klingon!" he exclaimed before he could stop himself. The Metamorphosis of Kahless wasn't to happen for more than a century.
"What transformation?" Phlox asked.
"Er ... hard to say really. They don't discuss it with outsiders."