If he has to repeat his loop from the desert - that's what we all think - , how could he pick up the horn???
Maybe it's a very very stupid question and I cry your pardon if it's obvious but I have been thinking of it for awhile and it gives me more questions.

If he has to start his quest from the desert he has NO chance to pick up the horn... Jericho Hill was ages before that...
So how does it work?