Backus saw Rachel pull out of the side lot of the FBI building in a dark blue Crown Victoria. She turned left onto Charleston and headed toward Las Vegas Boulevard. He hung back. He was sitting behind the wheel of a 1997 Ford Mustang with Utah plates. He had taken the car from a man named Elijah Willows, who no longer needed it. His eyes left Rachel's car and held on the street scene, watching for movement.

A Grand Am with two men in it pulled out into traffic from the office building next to the FBI building. It went in the same direction as Rachel's car.

"There's one," Backus said to himself.

He waited and then he watched a dark blue SUV with triple antennas pull out of the FBI lot and turn right onto Charleston, going in the opposite direction as Rachel. Another Grand Am pulled out behind it and followed.

"There's two and three."

Backus knew it was what was called a "sky bird" surveillance. One car to maintain a loose visual surveil- lance while the subject was tracked by satellite. Rachel, whether she knew it or not, had been given a car with a GPS transponder on it.

All of this was okay with Backus. He knew he could still track her. All he needed to do was follow the follow car and he would get there just the same.

He started the Mustang. Before pulling out onto Charleston to catch up to the Grand Am following Rachel, he reached over and opened the glove compartment. He was wearing rubber surgeon's gloves, size small so they would stretch across his hands and be almost unnoticeable from a distance.

Backus smiled. Sitting in the glove box was a little two-shot vest gun that would nicely complement his own remaining weapon. He knew he had sized Elijah Willows up perfectly when he had first seen him leaving the Slots-o-Fun on the down side of the strip. Yes, he was what Backus had been looking for physically- same size and build-but he had also sensed a detachment about the man. He was someone who dwelled alone and on the edge. The gun in the glove box seemed to prove that. It gave Backus confidence in his choice.

He hit the gas and pulled loudly out onto Charleston. He did this purposely. He knew that on the off chance there was a fourth car, a trailer, the car they would find the least suspicious would be the one with the driver boldly drawing attention to himself.

It came down to basic high school geometry. I had two of the three points on a triangle and I needed the third. It was that simple and that difficult at the same time. To get that point I had the total distances of all three sides of the triangle to work with. I sat down, opened my notebook to a new page and went to work with McCaleb's map.

I recalled from the Times article that the mileage recorded on the rental car of one of the missing men was 328 miles. Under what I believed McCaleb's theory to be, that mileage count would equal the total of all three sides of the triangle. I knew, thanks to the notations on the map page, that one side of the triangle-Zzyzx to the airport in Vegas-was 92 miles. That left 236 miles for the remaining two sides. That number could be divided in a variety of ways, putting the missing point of the triangle in a myriad of possible positions on the map. What I needed was a charting compass to accurately plot the triangle but I made do with what I had. According to the map's legend, one inch equaled 50 miles of terrain. I took out my wallet and removed my driver's license. Holding one of its short edges to the legend I was able to determine that the side of the license equaled 100 miles on the map. Working with that I composed a number of triangles that approximated the remaining 236 miles of roadway. I plotted points both north and south of the baseline I had drawn from Zzyzx Road to Las Vegas. I spent twenty minutes working the possibilities, my plotting taking the third possible point of the triangle down into Arizona and as far as the Grand Canyon and then north into the bombing and gunnery ranges under the command and restriction of Nellis Air Force Base. I soon grew frustrated, realizing the possibilities were endless and that I could have already identified the missing point of the triangle and not even know it.

I got up and went to the half-fridge for another beer. Still annoyed with myself I opened the cell and called Buddy Lockridge. The call went through to voice mail without being answered.

"Buddy, where the hell are you?"

I slammed the device closed. It wasn't like I needed Buddy there that moment. I just needed to yell at somebody and he was the easy target.

I stepped back out onto the balcony and checked for Jane. She wasn't there and I felt a glimmer of disappointment. She was a mystery and I liked talking to her. My eyes swept across the parking lot and the jets beyond the fence and caught on the figure of a man standing in the far corner of the lot. He had on a black baseball hat with gold lettering I couldn't read. He was clean-shaven and wore mirrored glasses and a white shirt. His lower half was hidden by the car he stood behind. He seemed to be looking right at me.

The man in the hat did not move for at least two minutes and neither did I. I was tempted to leave the apartment and go down into the lot but was afraid if I lost sight of the man for even a few seconds he would disappear.

We stood locked in our stares until the man suddenly broke from position and started walking across the lot. As he came out from behind the car I saw he wore black shorts and some sort of equipment belt. That was also when I could make out the word Security on his shirt and realized he apparently worked for the Double X. He walked into the passageway that separated the two buildings that made up the Double X and was gone from my sight.

I let it go. It was the first time I had seen a security man at the place in daylight but it still wasn't that suspicious. I checked the next-door balcony for Jane again- there was no sign of her-and went back inside to the dinette table.

This time I approached the geometry differently. I ignored the miles and just looked at the map. My prior exercise had given me a general idea of how far and wide the triangle could stretch on the map. I started studying the roadways and towns in this zone. Each time a location interested me I measured the distances to see if I could come up with a triangle of approximately 328 miles.

I had measured out nearly two dozen locations, failing to get even close on the approximation of mileage each time, when I came across a town on the north side of the baseline that was so small that it was denoted by only a black dot, the smallest demarcation of a population center in the map legend. It was a town called Clear. I knew of this place and I suddenly got excited. In a moment of flash thought, I knew that it fit the Poet's profile.

Using my driver's license I measured the distances. Clear was approximately 80 miles north of Las Vegas on the Blue Diamond Highway. It was then another 150 miles approximately on rural routes across the California border and down through the Sandy Valley to the 15 freeway and the third point of the triangle at Zzyzx. Adding in the baseline mileage between Zzyzx and the airport in Vegas, I had a triangle of approximately 322 miles, just 6 miles shy of the total put on the rental car belonging to one of the missing men.

My blood started to jump in my veins. Clear, Nevada. I had never been there but I knew it was a town of brothels and whatever community and outside services are spawned by such businesses. I knew of it because on more than one occasion in my career as a cop I had traced suspects through Clear, Nevada. On more than one occasion a suspect who voluntarily surrendered to me in Los Angeles reported that he had spent his last few nights of freedom with the ladies of Clear, Nevada.