The children with Gaius were frightened but doing a good job of controlling it, and a couple of them managed to work together to keep the Inferi away from one side of them while Gaius concentrated on the other. The shambling wrecks were everywhere, interspersed with screaming people and mad chaos as tents and tables and other debris went flying or was hurled toward targets.
He saw one woman go down as a chair came hurtling toward her, and he cursed under his breath as he saw an Inferi start toward her. He tried an Incendio, which unfortunately produced no more than a shower of sparks - magic was still not working quite right! There were too many children for him to Apparate them all out, even if he was certain it would work, and he'd already cast shield charms around their entire group. He had only a moment to make a decision, and with a snarl he did so, hurling himself toward the woman and interposing himself between her and the Inferi. He grabbed the back of her robes and began to pull her toward the group of children, keeping his wand levelled at the wreck of a human being which shuffled after him, its half-rotted mouth agape as it gibbered.
There were people flying overhead on broomsticks, and he called out. "Help! There are wounded!" He didn't stop moving, even as the Inferi gained on him. He could have run and left the woman, but he didn't, and he tried another Incendio. This one worked, setting the Inferi's clothing ablaze, and he sighed with relief as it collapsed.
"Professor! Look out!"
One of the students cried out to him in warning. He was almost back to the group, still pulling the weight of the woman, and he turned to look over his shoulder. That was when the Inferi he hadn't seen struck him with a clawed hand, scoring his cheek with its nails and almost knocking him off his feet. Stunned by the force of the blow, Gaius couldn't collect his wits, and he staggered, grimly holding to the fallen witch's robes to keep himself upright.