As Sam stayed behind to draw the Rabids away, using himself as bait to find a cure for the infection spreading through his own veins, Dean escorted Jenna and the infant to safety.
Tell me which character's perspective you'd like to dive into next. [S11E1] Out of the Darkness, Into the Fire
"We didn't have a choice," Dean snapped, though the conviction was hollow. As Sam stayed behind to draw the Rabids
If you want to explore more about this specific era of the show: The psychological bond between Sam’s secret struggle with the Rabid infection Castiel’s torture at the hands of the angels " Dean snapped