Harry responded with further Stunning Spells: Red and green collided in midair in a shower of multicolored sparks, and Harry thought wildly of fireworks, and the Muggles below who would have no idea what was happening — "Here we go again, Harry, hold on!" yelled Hagrid, and he jabbed at a second button.
As they reached the barrier, Albus winced, but no collision came.
Ron and Harry shouted together; their spells collided and the monster was blown backward, its legs jerking horribly, and vanished into the darkness.
Then, through the smoke, Harry saw a rectangular patch on the wall and steered the broom at it, and moments later clean air filled his lungs and they collided with the wall in the corridor beyond.
The bang was like a cannon blast, and the golden flames that erupted between them, at the dead center of the circle they had been treading, marked the point where the spells collided.
The jinx hit the middle Death Eater in the chest; For a moment the man was absurdly spread-eagled in midair as though he had hit an invisible barrier: One of his fellows almost collided with him — Then the sidecar began to fall in earnest, and the remaining Death Eater shot a curse so close to Harry that he had to duck below the rim of the car, knocking out a tooth on the edge of his seat — "I’m comin’, Harry, I’m comin’!"