 In the face of the advance of Hardee and Polk against the Union right, Sherman and McClernand mounted a fighting retreat in the direction of Pittsburg Landing, leaving the right flank of the Hornet's Nest exposed.Just after Johnston's death, Breckinridge, whose corps had been in reserve, attacked on the extreme left of the Union line, driving off the understrength brigade of Col. David Stuart and potentially opening a path into the Union rear and the Tennessee River.However, the Confederates paused to regroup and recover from exhaustion and disorganization, then moved toward the Hornet's Nest.