Her cell phone chimed. "That'll be Chambers," she said to her driver, Joe Menasria. With one hand, Dawna pressed her cell phone to her ear. With the other hand, she braced herself for the jolt she knew would follow when their liquid cargo shifted.

Across the doghouse from her, Joe released the trailer brakes with a whoosh of air, shifted out of neutral, and moved the chemical tanker across the truck stop lot toward the on-ramp.

"Heard it on the CB," Dawna reported to Benjamin Chambers, her Bureau colleague. Chambers and another agent had been at the I-78 rest area since eight o'clock that morning when the New Jersey State Police Hazardous Materials Enforcement Unit set up their roadside checkpoint--got the party started, in trucker lingo. "We're rolling, ETA fifteen minutes." She shut her eyes, concentrating on what Chambers was telling her over the phone.

Joe worked his way up through the gears and insinuated the eighty thousand pound vehicle into the heavy traffic racing east toward Newark. He smoothly coordinated his shifting with the shifting contents of the tank. Forty-eight hours earlier in North Carolina he'd loaded zinc and manganese nitrates combined with D-Blaze fire-retardant solution. The liquid fixing-preservative was so dense that weight restrictions hadn't allowed Joe to fill the tank to capacity and the glop had an extra thousand gallons of empty air-space to roll around in.

Dawna had joined him that morning at a truck stop near Allentown and after less than an hour riding shotgun in the Peterbilt, she knew that certain moves--gearing down too rapidly, hitting the brakes, stomping the accelerator--set the glop in motion, jerking the tractor-trailer combo and her body along with it. A full load of gasoline would have been easier on her spine, but gasoline wasn't exotic enough bait for US Department of Transportation Safety Inspector Andrew Darcy.

Darcy had been hired by USDOT in the wake of September 11th and the FBI had reports from three different truckers that he was on the take. Today he'd been scheduled to work at the I-78 checkpoint. Now, Chambers confirmed that the newly arrived van was the one assigned to Darcy. The target was in place.

Dawna ended her conversation, snapped the cell phone shut. "We'll get him this time," she yelled to Joe.

Joe nodded, tightlipped. He had both hands on the oversize steering wheel and his gaze kept moving, from the traffic ahead to the rear view in his side mirrors and back again. He'd turned the air conditioner off and diesel exhaust fumes wafted through the open window, thickening the muggy soup that passed for air in northern New Jersey in July.

From the sleeper, the black toy poodle moaned in complaint and resumed her panting. Dawna ignored the animal. Dawna was hot, too, but she wasn't whining. Joe claimed that the air conditioner drowned out sounds and signals from other traffic and she damn well wanted him to have all the information he needed to get the truck up to speed. The trailer was labeled with diamond-shaped placards bearing the number 1760 and the number 8 and an alarming graphic of test tubes spilling. The "1760" stood for the contents, monoethanolamine. The "8" meant corrosive--a mild-sounding term for a chemical combination that would burn the flesh off of Dawna's finger if she were foolish enough to dip it into the soup. Corrosive--but not combustible, not flammable, not explosive. Some comfort, but not much for the FBI operative posing as the driver's wife.