Getting the slide the user will continue from if they re-visit the course and switching language

Thanks Sam, that was the conclusion I had reached too. It's complex but manageable as there are only 20 slides per story and 3 languages (stories). The only issue I have is when people re-visit the module, the logic I need to apply is:

User revisits module (slide 5 of scene 2) -> user is re-directed to language selection -> user is then re-directed to the corresponding language slide if a different language is selected (slide 5 of scene 3)

The re-direct logic is fine but I can't find a way to find out if the user has re-visited the module or a way to fire some logic only once so there is no re-direct loop on every slide. I guess a Javascript session or using the system date would be possible but is there a better way? Variables persist when re-visiting so I can't see a way to achieve this with variables alone.

Thanks