[allmendream]

You mean John Carter's two wedding rings? In the books he was never previously married.

Did you mean the transport devices? The Barsoomian “Ruby Red Slippers” that would have sent him home?

[longtermmemmory]

you mean a device vs a cave with mystic gas? (I found the device more plausable)

I know it is not constent with the books but it did work with the desire not to “go to war” again. It does track the fight for the people vs some cause.