Because of the story’s opening, I’m convinced the Twonky is from the future. The “temporal snag” that brought it to 1942 feels like an unexpected time rift to me, although the route back to the future is an intentional journey via an unexplained method.
Nowadays, we all know that Doc Doom is far too smart to think the most profitable way to use his time platform is by sending three of the FF into the past with orders to bring back Blackbeard’s treasure (while keeping the fourth member of their team captive). And yet, the story has a charm that stems from the causal loop of Ben Grimm’s presence in the past actually causing the legend of Blackbeard, which in turn caused Doom to send the loveable lunk back.
The story has a classic self-defeating act: The Terminator goes back in time to kill Sara Connor, causing Kyle Reese to follow and become romantic with Sara Connor, causing John Connor to be born and eventually lead the revolution, causing the Terminator to go back in time to kill Sara Connor, . . .