Hmmm... I was thinking, if someone from tribe b came to tribe a and told them about tribe b being captured (having escaped the scientists themselves)? That way they have a chance to get back in.
Could provide a different motive for tribe a and b to get together. But we can probably only choose one or the other. Unless they meet escapee from tribe b on the way?
Elizabeth: "There will come a moment when you will have a chance to show it. To do the right thing." Jack: "I love those moments. I like to wave at them as they pass by."
