priori incantantem.

A jet of green light issued from Voldemort's wand just as a jet of red light blasted from Harry's—they met in midair—and suddenly Harry's wand was vibrating as though an electric charge were surging through it; his hand seized up around it; he couldn't have released it if he'd wanted to—and a narrow beam of light connected the two wands, neither red nor green, but bright, deep gold... he felt his feet lift from the ground.