The lines intermingled in the darkness. Sergeant John Berry of the 8th Arkansas Infantry Regiment wrote that "the approach of night made it difficult to tell foe from friend." Liddell's Brigade fired upon a "dark line" of soldiers near the Benton Road, close to the intersection. Suddenly, the obscured troops yelled that they were friends. Liddell's Brigade ceased fire, and Polk rode forward to investigate, asking the colonel of the mysterious regiment why he had been firing upon "his friends." The officer replied that he was shooting at the enemy. "Enemy?" Polk scoffed. "Why I have only just left them myself -- cease firing, sir; what is your name, sir?" The officer replied, "My name is Colonel [Squire Keith] of the [22nd Indiana Infantry Regiment], and pray sir, who are you?" Polk realized that he was behind enemy lines, and thinking he would be killed at any moment, he decided to "brazen it out." Riding down the line, he pretended to be a Union officer and ordered the Yankee troops to cease fire. He then spurred his horse back to Liddell, sputtering, "General! Every mothers son of them are Yankees." The Confederates unleashed a volley and, Polk wrote, hundreds of muskets "blazed as one gun." He added that "the slaughter of that Indiana regiment was the greatest I had ever seen in the war." The 22nd Indiana suffered nearly 70 percent casualties, the hightest percentage of any regiment at Perryville. It was caused by the men of Buckner's Division, thanks to Polk's ruse.