Originally Posted by
DownUnderFlyer
Technically you need a return ticket to Iceland as in the event you don't fly the last leg they can charge you for all the one way flights you took during your RTW tour.
I double checked with Lufthansa about this and they said not completing a let will invalidate all the remaining legs, that's about it. They have not heard of any case of a customer being charged extra for not completing a leg so it's probably never happened.
If a rule like this existed it would be pretty ridiculous cause one may decide to abort a RTW due to so many personal reasons, perhaps they fell ill and could not complete the last leg etc. are they going to suddently incur hundreds or thousands in extra charges? I don't believe that would be a reasonable expectation.