“Nothing,” Monk said hastily. He should say nothing . . . not yet. His mind raced. What on earth could have happened? She would never, ever have jumped! Not Katrina Harcus. She was on the edge of exposing an ancient wrong. She wanted revenge, and she had had it almost within her grasp. And Dalgarno was innocent, which was what she had wanted above all from the beginning.

A uniformed constable came across the pavement, pushing his way past the bystanders who had begun to gather. “Got a witness, sir,” he said to Runcorn. His face was pinched and unhappy, expression exaggerated in the shadows cast by the street lamp. “Says there were two people up there, quite definite. ’E saw them strugglin’ back and forward. ’Eard ’er scream out summink, and then she staggers back an’ ’e comes after ’er, an’ next thin’ ’e turns, an’ she’s gorn over the edge.” He looked down at the figure on the ground. “Poor creature. Looks like she were youn’ . . . an’ right ’andsome too. It’s a cryin’ shame.”

“What happened to the man?” Runcorn asked, glancing at Monk, then back to the constable.

The constable straightened up. “Dunno, sir. I asked the witness but ’e didn’t see. Light was very fitful, like. ’E saw ’er partic’lar because of ’er wearin’ white an’ all. Man were in summink very dark, an’ ’e’ad a cloak on, sort o’ . . .” He shrugged. “Well, a cloak. Witness says ’e saw it billowin’ out when they was fightin’ just before she went over.”

Monk felt sick imagining it, Katrina struggling with someone, crying out for help, and no one did more than watch! They did not even know who had been there on the roof fighting with her . . . killing her! Dalgarno? It must have been. He was the only person involved. He must have come here when she had contacted him, as she had told Monk she would. Something she had said, some evidence she had found and he had missed, for all his meticulous searching, had driven Dalgarno to defend himself this murderous way.

But what? How had he committed the fraud? Why had Monk not been able to find it? Why was he so stupid, so blind all over again? And now someone else was dead, another he had been doing everything he could to help. He had promised her . . . and failed.