The HBO prequel fills in the vast universe of “Dune”— but has our own galaxy in mind, too.

The ancient conflict, known as the Butlerian Jihad in Frank Herbert's books, will be glimpsed in HBO's new prequel series.

That may have been the only move Dune: Prophecy could have made, but it’s one that relies on viewers having an interest in its franchise’s world beyond what Villeneuve and his cast brought to their Dune films. That’s a gamble that may work ...