I guess I should also add that the 2nd Grace scene is basically doing all the chain of events during the swim competition. After doing a few of the steps, MC will think to cast a calming spell on Grace, which has some... interesting side effects? Trying to be vague about it. If you want the exacts, I'd have to go back through to remember the steps. Basically just do the explore option a lot to get the other options going, iirc you get it after using the oil on Meryl.