Agent Richard07 wrote:
^ That's a pretty good way to go about things. I was wondering if it were possible to introduce the mother without the audience knowing it was her and that fits the bill.
Another way they could do it is go ahead and introduce the mother tonight or early next season, but not have Ted actually meet her. Spend all of next season getting to know the mother through Barney/Robin/Marshall/Lily flashbacks until one of them decides to set her up with Ted in the series finale.
Officially, they will have met in the series finale. Unofficially, we will have known her the whole season. Hilarity can ensue with them not meeting each other for a year despite knowing all of Ted's friends.