She is still holding the letter, and suddenly she doesn’t want to be. She hands it across the seat to Bell, who passes it to Cooper. Cooper puts it into his inside jacket pocket without glancing at it.

“So where do me and Bell fit into all this?”

“You’ll be in the sheriff’s office in Annandale during the stakeout.”

“But can’t we—”

“Lewis, I can’t take you—there’s gonna be a lot of guys with guns on-site, and you’re both civilians. Don’t go getting all sore on me, this might just turn into a long wait. The Butcher might not expect a reply from Gutmunsson within forty-eight hours of having sent the original letter.”

“Okay.” Emma chews a thumbnail.

“Nothing might happen today. But we’ve got to assume that if the Butcher’s waiting on a reply, he’ll drop by every day until Gutmunsson’s letter arrives. There’s a good chance we might scoop him up today or tomorrow.”

Cooper’s energy crackles in the car interior. When he steers around a corner, Emma notices that his gun holster prints against his jacket—he’s wearing his sidearm. While she was in the timeless zone with Simon Gutmunsson, Cooper and Bell have been out in the world tracking prey. It seems as if the prey might finally be turning in their direction.

Cooper looks up. “One last thing, for both of you. Operations like this, we’re talking lots of officers from multiple departments, lots of competing egos. Keep your eyes open and your questions for a suitable time. If you’re confused, wait for direction and I’ll give it.”

Trees whip by on the Beltway before the river, and now the car is over the water. The cirrus clouds Emma noticed earlier have lowered and thickened. It’s dizzying to realize it’s not even ten in the morning.

Saplings along the side of the 236, then the tidy main street and the tough red brick of the old Fairfax courthouse building. Cooper turns left onto West Street, finds a parking space near a sixties-style high-rise. They enter the sheriff’s office through a service door, and when Emma sees the typical dropped ceilings and tile light fixtures, she knows where she is.

A bustle of people inside the hallways, uniforms in various shades of fawn and brown and SWAT black. Cooper goes through the processes of check-in and introductions with a rapidity that reminds everyone they’re short on time.

A man in a postal uniform is waiting for them in a deputy’s office. Emma assumes he’s an undercover cop before realizing he’s an actual mail carrier. Cooper shakes the guy’s hand while Simon’s reply—the envelope and the letter itself—is being photocopied, then the original is folded back up. A stamp is applied, and also a redirect label that Bell got from Georgetown U. The mail carrier won’t add an official postmark, though. Cooper chews his lip, then borrows an ink pad at the station’s duty desk to add a blue smudge that makes the letter look more official while satisfying USPS propriety. The mail carrier nods and departs.