Colonel Thorne was into content. At dawn he was riding his horse down the Antietam toward the Potomac, and by the time the fog had lifted he had marked a half dozen crossing places on his map. He had attempted to cross one ford and been repelled by an alarmed shout from a gray-clad picket who had hastily cocked his rifle and fired a wild shot that whipped over Thorne’s head. Further upstream he had watched a stone bridge and tried to count the number of rebels dug into their rifle pits on its far side. He saw them go down to the creek to fill their canteens, watched them wash, and listened to their laughter.

Now, as the morning dragged somnolently onward, he discovered General McClellan comfortably ensconced in the Pry house. Telegraphers were running wire up the hill to a signal station on the Red Hill’s summit from where messages would be semaphored by relay stations until another telegraph station could send McClellan’s news to Washington. One message already waited to be sent and Thorne, discovering the telegraphers setting up their equipment in the Pry’s parlor, picked it up. “This morning a heavy fog has thus far prevented us doing more than ascertain that some of the enemy are still there,” the message read. “Do not know in what force. Will attack as soon as situation of the enemy develops.” Thorne snorted as he dropped the message. You don’t wait for the enemy, he thought. My God, but Adam Faulconer had died to put the Northern army into this place and all McClellan needed to do was order his troops forward. Those troops were in high enough spirits. They had chased the rebels off the mountain passes and rumors were whipping through the Northern ranks that Lee was wounded, maybe dead, and so were Jackson and Longstreet. The troops were willing enough to fight, but McClellan was waiting for the situation of the enemy to develop, whatever that meant. Thorne strode out of the parlor to discover the General sitting in one of a number of well-upholstered armchairs that had been placed on the lawn to give a view of the ground across the river. A telescope stood on a tripod beside the General, while in front of the armchairs, on the lawn, which sloped steeply downhill, a barricade had been erected from fence rails and tree branches. The barricade suggested that McClellan believed he might have to make his last stand here on the farmhouse lawn, firing his revolver from the comfort of an armchair while his defeated troops streamed past on either side.

“I have been south,” Thorne said abruptly. McClellan, chatting with Pinkerton, who occupied the armchair next to his, had pointedly ignored the colonel’s arrival and so Thorne simply butted in.

“South where?” McClellan finally asked.

“South down the creek, sir. There are fords there, and none of them properly guarded by the rebels. One had a picket, but only a handful of men. The best crossing is at Snaveley’s Ford.” Thorne held out his notebook in which he had penciled a crude map. “Cross there, sir, and within a mile we’ll have cut off Lee’s retreat.”