h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

"In fact Chani and Paul's first son, Leto, who is killed in the novel, doesn't appear in the film at all"

Which Leto does this refer to, exactly? Duke Leto, father of Paul, or Leto II, the son of Chani and brother to Ghanima, who definitely did NOT die in the novel and in fact did not appear until the end of Dune Messiah and who would eventually become the God Emperor of Dune, or is there a third Leto that I can't remember?

I haven't read the original novel in quite a while, but I have a copy of Children of Dune in front of me now.

There was a third Leto. After Paul's father Leto died, and before Paul and Chani had twins, one of whom was called Leto, the other Ghanima, Paul had a son called Leto who was killed at the same time that Emperor Shaddam IV captured Alia.
Leto II is in fact the third Leto that we know of in the Dune books