The Mystery of the English Return to Roanoke

The first settlement in 1585 is around 100 men and they return the same year with Sir Francis Drake back to England. And it's when they return that the mystery starts to unfold, isn't it? They would be very much reliant on these new supplies being brought from England but because of all these reasons to do with conflict and climate, it's not always possible. So I guess it was never intended that people would go and never leave.