My name among the camaradas was now Assassino da Alimárias, which I’m given to understand means “slayer of beasts.” I received the news with grim amusement.

We had far to go, and many more such perils to face. I decided then that where the slaughter of such monstrous game was required, I would forever stand ready.

BREAKFAST THE NEXT MORNING WAS TAKEN IN THE BAR, BECAUSE the dining room was in use. The true prophets, those senior detective officers with the city’s glamour on them, had arrived to take over.

Sebastian sat behind his kippers at a corner table and watched all the comings and goings with mixed feelings. The tall, straight detectives in their immaculate overcoats and bowler hats were attended by a squad of clerks and sergeants that ran ahead of and around them. Messages were flying, and there were scenes to be visited. Despite the tragedy at the heart of it all, he felt a certain nostalgia. Such had been his life, once.

After that he went up to his room and prepared himself to go out. This time, he found his belongings undisturbed. There was little he could do to protect himself against further searches, whether by curious staff or by someone with a more sinister motive, other than to ensure that he kept his notebook and valuables about his person. An intruder would find nothing of advantage in his shaving kit or linen.

He’d cleaned up his own boots, knowing that he could expect little in the way of extra service under the circumstances. He stowed his letters of authority in one pocket, his copy of Sir Owain’s book in another.

An Amazonian expedition had taken place. That was beyond doubt. And that it had met with disaster could not be doubted either. But as he’d told Stephen Reed, no true or satisfactory account of that disaster had ever been given.

Lancaster had funded the trip himself, with the intended purpose of taking celestial measurements from one of several key points around the globe. The measurements were needed to support his patented system for aiming large guns by the stars. He had set off into the jungle with vehicles, mules, experts, porters, and an enormous caravan of instruments and supplies. He’d returned with none of them. Just himself, and one other survivor. The survivor had suffered injuries and a level of delirium that had left him permanently hospitalized.

As a consequence, Sir Owain’s Royal Society lecture, in which all was to be revealed in detail, had attracted wide attention. The promise of sensational revelations, with no hint as to what those revelations might be, had stoked the public’s interest. The original meeting-hall venue had been ditched in favor of the Queen’s Hall in Langham Place, a concert theater of much greater capacity. Several newspapers requested advance interviews, but were turned down. Sir Owain’s book was scheduled for publication within a matter of weeks, but no page proofs or early copies could be located.

Even the society’s president had known nothing of what was to come. Following his introduction, Owain Lancaster had begun with a warning: that what followed might be hard to believe, but was true nonetheless. For much of it, he could offer no evidence beyond his own observations. His public testimony was underwritten by his private grief. He owed it to the dead to tell the whole truth.

The whole truth, as he told it, was that the expedition had been wrecked by an early accident on the river that was carrying them downstream, after which the party’s survivors had been stalked by monsters. The monsters rarely showed themselves and were mainly known from the evidence of their attacks. Of all the party, Sir Owain was the only one who saw them fully with his own eyes. They included a serpent that tried to wreck the rescue boat that was carrying him home.

The first ten minutes of Sir Owain’s talk were received in silence. The next five played to a growing rumble of conversation among the rows. His lantern slides were met with loud heckling and open derision, and the rest of his words went unheard; most of the audience was on its feet by then, and the ushers struggled to keep any kind of order. Some object was thrown, and something close to a riot followed. The speaker persisted and had to be stopped. Sir Owain was hurried from the building by a service door. His lantern slides, which featured some photographs but were mostly artists’ realizations of the monsters made under Sir Owain’s direction, were stolen during the upset.

But they were no loss. Those same images appeared as plates in the published account, which went on sale shortly after. Its publishers, who’d been hovering over a decision to withdraw the book, found themselves with a runaway success.

They were half embarrassed, half elated; they did their best to follow a line that allowed them to keep both their dignity and their profits. And so, as Sir Owain suffered public opprobrium and the censure of the society and withdrew to his West Country estate, they continued to sell copies of “this remarkable document, the subject of so much lively and continuing debate.”

Stalked by monsters, torn by beasts. And an estate on which, it now seemed, people vanished and young girls of a certain age and development could not play in safety.

As Sebastian’s predecessor had first noted, there seemed to be something more than coincidental misfortune at work here.

WHEN SEBASTIAN stepped out into the main street, he could see that new activity had begun around the assembly rooms. Locals were again gathering outside. A hearse wagon and two undertakers’ men waited by the doors. Becoming aware of two women passing behind him, Sebastian tipped his hat to them; they didn’t even notice. He heard one telling the other that the parents had arrived and had gone in with the police. The women went on to join the assembly room crowd, and Sebastian turned away.

The grief of the parents would be a hard sight to bear. He understood that there was a low point in any journey such as theirs. Some called it the hour of despair; others, the suicide hour. The notion was that if one could pass through it, then hope would begin. The hour could be deferred, or it could be ignored for a while. But if life were to continue, it could not be avoided. How did one pass through a loss so profound? He couldn’t begin to imagine it.

The town’s one-roomed museum and library was on a steep little street that led down to the harbor. It was a humble whitewashed building with a surprisingly grand door. There was an imposing house above it, and less imposing houses below.

Sebastian tried the door. It was unlocked, so he went inside.

It was historical exhibition and reading room combined. Arnmouth’s modest history was covered by six glass cases of coins and other objects, some Roman stones, and a dozen or more framed oil paintings of local estates. The farther part of the room featured two long tables with eight chairs to each. Beyond them was a counter, behind which was a woman. She seemed surprised by his presence.

Raising her voice to reach him, she said, “I don’t open until nine thirty.”

Sebastian glanced back. “Your door isn’t locked,” he said.

“I don’t need to keep it locked,” she said. “Everybody knows I don’t open until nine thirty. What do you want?”

He’d reached the counter now. The woman had iron-gray hair, pinned up. She wore a high-collared blouse and she held herself straight. Despite his transgression, she didn’t seem ready to order him out, and so he decided to press his luck.

Sebastian said, “Do you keep a local newspaper?”

“In the racks,” she said, “over there.” And she pointed to a frame where three or four broadsheets hung from rods, café-style. “Leave it out on the table when you’re finished.”