Page 168 of Slack Tide Kill

"I don't know his full name. Just what my dad called him." He licked his lips. "Uncle Jack."

Realization slammed through Sally like an electrical arc.

Uncle Jack. 60 years old. Emergency services. Tied to the land. Close to Arthur Bledd.

She tried to speak but the revelations kept flooding in. Quoting John Donne. His chaotic life in London, his ordered life on the Rother. DCI Stewart as a second father. And Heraclitus…

Ephesian Tears!

The words leapt into her mind unbidden, swiftly resolving to the name of the houseboat moored next to Arthur Bledd. She'd never really grasped it before, but it was right there in plain sight. Heraclitus was from Ephesus. His nickname was the weeping philosopher!

It felt like she'd been cored out. A man she'd never looked at twice, never suspected. A man who'd seemed broken by the original investigation, a man taking refuge from his past, a man doing everything he could to help them.

The same man who'd murdered Tom Richter. Jason Harrow. Nancy Cagen. Emily Chakrati. Arthur Bledd. Nia Mensah.

"Jack Mercer," she whispered.

"Holy shit," Liam murmured by her side. "Really?"

She pictured Mercer just a few hours ago, lending a hand around the station, offering his expertise. The killer come to gloat, as he had so many times. He could have slipped in and warned Rook not to talk at any point. As far as she knew, he was here in the station still.

"Come on," she barked and ran out, eyes roving the bullpen. No sign of Mercer. She turned and dashed down the corridor to Mayhew's office, throwing open the door.

Empty.

She ran back, Liam right at her heels, to stop in front of their team.

"What is it?" Gemmell asked.

"Ex-DI Jack Mercer, where is he?" Sally asked.

"I, uh…" Gemmell's face paled. "Why, do you think–"

"Where is he, Stephen?"

"He's gone! Twenty minutes back, maybe? It's crazy, in this storm, but the DI just paced right out, then the DCI ran right after him."

Sally reeled. "What? DCI Mayhew followed him?"

"That's right. I told you she'd left. What's happened."

"She left? Where were they going?"

"I've got no idea. I–"

Sally tuned him out and turned to Liam. This was impossible. The worst possible situation; their DCI as a hostage. "Where could he be taking her, Liam?"

Liam nodded, processes turning in his eyes. "He's been here the whole time, Sally. He's been read-in to everything. He knows all the leads we've been pursuing. So–"

"So he knows we're onto him! This is it. Endgame."

"Endgame," Liam repeated. "With DCI Mayhew along for the ride. Maybe his final victim? But why her? And where?"

Sally's mind raced. "They're close; he was best friends with her father, until he died." She looked out over the bullpen as if seeking inspiration. "Mercer provided stability for her, until he left for London."

"A year after he killed Tom Richter," Liam said.

"He killed Richter?" Gemmell said. Still catching up.