On the battlefield, Henry hears it, but slow, like a record being played on the wrong speed. He turns and sees the speaker. In the present, Skeet and Keel look over the field where the battle once took place. Skeet says it'll never work. "It worked on aisle three," Keel reminds him. On the battlefield, the sound of the recording gradually speeds up until Henry understands it, and collapses. You know, since Henry had no way of double-checking, Skeet could have lied to him and Henry would have had no way of knowing. And let's say they had found out William and Isabella had died. Wouldn't that have made Henry go all poltergeist?
"Mommy, look!" says Gus. From the battleground, lights are glowing and floating up into the sky. "Ghost lights," says Skeet. "Spirits of the Civil War dead." We pull in for a shot of a reflective Skeet watching the light show.
And back into Boston, a similarly reflective Skeet looks at the photo of Henry's battalion, which I guess he STOLE FROM THE HISTORICAL SOCIETY.
So, did he make it with the yummy mummy or what?