My room was small, and had a view of what looked like a back alley. But the Roman Forum was in sight from my room, just as the hotel’s brochure promised, although you had to peer through alleyways of brickwork to make out the fallen pillars and strolling tourists. But that brickwork, I found out later, was itself a ruin of a development called Trajan’s Market, a kind of giant shopping mall of antiquity. Anyhow the restricted view kept the price of my room down.

I unpacked, and searched unsuccessfully for a tea maker. The only English-language TV channel was CNN. But the room had an Internet connection, workable through the TV for the hire of a portable keyboard for a charge of a few euros, or a few thousand lira, according to the yellowing, outdated note on the TV cabinet.

I found a series of emails from Peter, sent from wherever he was ensconced with his Slan(t)ers in America. I paged through most of it, filing it in my mental category of “Peter’s spooky stuff”—and enduring the occasional heart-stopping moment as the connection, always slow, threatened to freeze altogether. Some of it was kind of interesting, though.

One of the Slan(t)ers’ principal activities was to search the world’s media for “anomalies”—any peculiar patterns, inexplicable events, that might show the fraying of the fringe of our worldview. It’s a hobby that’s been enjoyed by the UFOlogists since the fifties, I understand. And of course the rise of the Internet has turned this into an industry: the Slan(t)ers had search and pattern-recognition software, more powerful than the fastest commercial search engine, Peter boasted, capable of picking through the vast slurry of information, rumor, hoax, and plain garbage that pours onto our information superhighway every day.

And, Peter said, while he had been in the States this endless searching had turned up something about his mysterious dark matter.

“If a chunk of dark matter were to pass through the Earth, we wouldn’t see it. It would just pass through the planet’s substance. But its gravitation would trigger seismic events: shock waves in the Earth’s structure radiating away from its path. And, happily, we monitor seismic activity quite comprehensively . . .”

There is a global network of some five thousand government-sponsored seismic survey sites. They listen for the songs of the Earth, the great low-frequency waves that travel through the planet’s crust. What the government monitors specifically look for are waves emanating from a single point source, which could be the location of an earthquake, say, or an illegal underground nuclear test. “Clean” signals of that kind are extracted from the data and published. The rest of the information is written off as meaningless noise. “And much of it probably is,” said Peter. “You can get a seismic signature if a heavy truck passes by your station.”