Harry grabbed Hermione under her arm as a dark shadow appeared in front of them. Snape cast a quick succession of precisely uttered spells, blocking the two of them. Only one Auror had survived from the group and they were outnumbered by Death Eaters and Dementors but Snape’s hexes flew quickly and he was mostly focused on Bellatrix. Harry was helping clear the way by hexing Death Eaters.