Keller stopped ten feet away.
“So did I.”
“Police investigation. Back up.”
Keller pulled his credentials fully into view.
“Federal Bureau of Investigation.”
Mercer stared at the badge.
Then he looked around.
Lena had approached from the opposite side, credentials raised.
Another agent came from the west path.
A fourth stood near the street.
The civilians filming the encounter had suddenly gone silent.
Mercer looked at Isaiah.
For the first time, uncertainty entered his face.
“What the hell is this?”
Isaiah did not answer.
Keller pointed toward the handcuffs.
“Remove them.”
Mercer looked between the agents.
“Who is he?”
“Remove the cuffs.”
“He refused to identify himself.”
Keller's face hardened.
“I am giving you a professional courtesy by asking one more time before I involve your watch commander. Take the cuffs off Special Agent Cole.”
Mercer's mouth opened.
Nothing came out.
His eyes moved slowly toward Isaiah.
“Special Agent?”
Isaiah turned his head enough to meet his stare.
“Yes.”
The officer's face lost color.
Keller stepped closer.
“FBI Special Agent Isaiah Cole. He is part of an active federal investigation that you have just interfered with.”
Mercer immediately reached for the handcuff key.
“I—I didn't know.”
Isaiah's voice remained calm.
“No, you didn't.”
The first cuff opened.
“You should've told me.”
Isaiah slowly brought his arm around.
“You never gave me a safe opportunity to do that.”
The second cuff released.
Mercer swallowed.
“You could have just shown me your badge.”
“And compromised six weeks of surveillance in front of a suspected counter-surveillance operative?”
Mercer looked around the park again.
Suddenly every ordinary pedestrian seemed suspicious to him.
Keller stepped between the officer and Isaiah.
“You were told to disengage.”
“He never said FBI.”
“He told you there were circumstances you didn't understand.”
“That's not the same thing.”
“No,” Keller said. “But neither is sitting on a park bench the same thing as committing a crime.”
Mercer's face tightened again.
Some of the embarrassment was turning back into defensiveness.
“We had a call.”
Isaiah rubbed the red marks forming around his wrists.
“What did the caller report?”
Mercer hesitated.