On the visual A track, lay historic footage of the carnage in the trenches of Verdun or the Somme.
On the B track, lay a closeup of your hero in doughboy helmet and tunic (shot on a chromakey backdrop). Then instruct your switcher or software to combine the two visuals, and add a black and white filter effect to make your soldier match the scene. Voila! Your boy is in the middle of the Great War.
