From time to time, I do consider that I might be mad. Like any self-respecting lunatic, however, I am always quick to dismiss any doubts about my sanity.

I saw no reason to search the study for a hidden switch that might convert it again into the black room. Logic suggested that the formidable power needed to open that mysterious doorway had been projected not from here but from the other side, wherever that might be.

Most likely Fungus Man was unaware that his sanctum served not merely as a catalogued repository for his homicidal fantasies but also as a terminal admitting bodachs to a holiday of blood. Without my sixth sense, perhaps he could sit here, happily working on one of his grisly files, and not be conscious of the ominous transformation of the room or of the arriving hordes of demonic entities.

From nearby came a tick-tick-tick, a bone-on-bone rattle that brought to mind Halloween images of ambulatory skeletons, and then a brief scuttling sound.

I rose from the chair and listened, alert.

Tickless seconds passed. A rattle-free half minute.

A rat, perhaps, had stirred in the walls or attic, made sick and restless by the heat.

I sat once more and opened the desk drawers one by one.

In addition to pencils, pens, paper clips, a stapler, scissors, and other mundane items, I found two recent bank statements and a checkbook. All three were addressed to Robert Thomas Robertson at this house in Camp's End.

Good-bye, Fungus Man; hello, Bob.

Bob Robertson didn't have the necessary malevolent ring for the name of a would-be mass murderer. It sounded more like a jovial car salesman.

The four-page statement from Bank of America reported upon a savings account, two six-month certificates of deposit, a money-market account, and a stock-trading account. The combined value of all Robertson's assets at Bank of America amounted to $786,542.10.

I scanned the figure three times, certain that I must be misreading the placement of the comma and the decimal point.

The four-page statement from Wells Fargo Bank, accounting for investments in its care, showed a combined value of $463,125.43.

Robertson's handwriting was sloppy, but he faithfully kept a running balance in his checkbook. The current available resources in this account totaled $198,648.21.

That a man with liquid assets of nearly one and a half million dollars should make his home in a shabby, sweltering casita in Camp's End seemed downright perverse.

If I had this much green at my command, I might continue to cook short-order now and then purely for the artistic satisfaction, but never for a living. The tire life might not in the least appeal to me any longer.

Perhaps Robertson required few luxuries because he found all the pleasure he needed in ceaseless bloody fantasies that gouted through his imagination.

A sudden frenzied flapping-rattling almost brought me up from the chair again, but then a sharp and repeated skreek identified the source as crows pecking out their turf on the roof. They come out early on summer mornings, before the heat is insufferable, spend the afternoon in leafy bowers, and venture out again when the gradually retreating sun begins to lose some of its blistering power.

I am not afraid of crows.

In the checkbook register, I pored back through three months of entries but found only the usual payments to utilities, credit-card companies, and the like. The sole oddity was that Robertson had also written a surprising number of checks to cash…

During the past month alone, he had withdrawn a total of $32,000 in $2,000 and $4,000 increments. For the past two months, the total reached $58,000.

Even with his prodigious appetite, he couldn't eat that much Burke amp; Bailey's ice cream.

Evidently he had expensive tastes, after all. And whatever indulgence he allowed himself, it was one that he couldn't purchase openly with checks or credit cards.

Returning the financial statements to the desk drawer, I began to sense that I had stayed too long in this place.

I assumed that the engine noise of the Explorer pulling into the carport would alert me to Robertson's return and that I would be able to slip out of the front as he entered by the side door. If for any reason he parked in the street or came home on foot, however, I might find myself trapped before I discovered that he had arrived.

McVeigh, Manson, and Mohammad Atta seemed to watch me. How easily I could imagine that genuine awareness informed the intense eyes in those photographs and that they glinted now with wicked expectation.

Lingering a moment longer, I turned backward through the small, square day-date pages on the desk calendar, searching for notations of appointments or other reminders that Robertson might have written during recent weeks. All the note lines were blank.

I returned to the current date-Tuesday, August 14-and then flipped forward, into the future. The page for August 15 was missing. Nothing had been written in the calendar after that date for as far as I cared to look.

Leaving everything as I had found it, I rose from the desk and went to the door. I switched off the overhead light.

Golden sunshine, trimmed into flame shapes by the intervening bladelike leaves of the melaleuca, made a false fire on the sheer curtains, without greatly illuminating the room, and the emboldened shadows seemed to gather more heavily around the portraits of the three killers than elsewhere.

A thought occurred to me-which happens more often than some people might suppose and certainly more often than I would prefer- whereupon I switched the light on again and went to the bank of file cabinets. In the drawer labeled R, I checked to see if, among these dossiers of butchers and lunatics, Fungus Man kept a file on himself.

I found one. The tab declared: Robertson, Robert thomas.

How convenient it would have been if this folder had contained newspaper clippings concerning unsolved murders as well as highly incriminating items related to those killings. I could have memorized the file, replaced it, and reported my findings to Wyatt Porter.

With that information, Chief Porter could have figured a way to entrap Robertson. We could have put the creep behind bars before he had a chance to commit whatever crimes he might be currently contemplating.

The file, however, contained but a single item: the page that was missing from the desk calendar. Wednesday, August 15.

Robertson had written nothing on the note lines. Apparently, in his mind, the date itself was significant enough to include as the first item in the file.

I consulted my wristwatch. In six hours and four minutes, August 14 and August 15 would meet at the midnight divide.

And after that, what would happen? Something. Something… not good.

Returning to the living room, to the stained furniture and the dust and the litter of publications, I was struck once more by the sharp contrast between the well-cleaned and well-ordered study and the rest of the residence.

Out here, engrossed sometimes in raunchy magazines and sometimes in romances innocent enough to be read by ministers' wives, evidently oblivious of forgotten banana peels and empty coffee mugs and dirty socks long overdue for laundering, Robertson seemed to be unfocused, adrift. This was a man of half-formed clay, his identity in doubt.

By contrast, the Robertson who spent time in the study, creating and tending to those hundreds of files, surfing websites dealing with serial killers and mass murderers, knew precisely who he was-or at least who he wished to be.