How did the baby get left at the wall?
At the start of the film, when the guardian of the wall brings baby Tristan to his father, he says "this was left at the wall for you."
But how did the mother get the baby to the wall seeing as she could hardly walk a metre because of the magical chain..?
It seems unlikely that she asked the witch to drop him off, as she seems like the type who would prefer to keep the baby for her own even plans.
So how did baby arrive at the wall? Plot hole?