In 1864 a Secret Service agent for the Union army goes undercover in Richmond and pretends to be a Confederate captain. In 1864 a Secret Service agent for the Union army goes undercover in Richmond and pretends to be a Confederate captain. In 1864 a Secret Service agent for the Union army goes undercover in Richmond and pretends to be a Confederate captain. In 1864 a Secret Service agent for the Union army goes undercover in Richmond and pretends to be a Confederate captain.