[ The game is rigged. What a terrible thing to remind her of and for a moment she considers not telling Waver. Wouldn't he have known all this time..? Her father knew, but did the rest of the magi from the Fourth Holy Grail War know..? ]

Rider... Waver, um, there's something I have to tell you about the Grail.

In order to make a wish, it requires seven souls to be placed back within it to unlock it.