So, Grindelwald has been revealed and the search for the real Percival Graves begins. Records are being reviewed and one entirely oblivious HR witch says, "He's taken leave for a family emergency. Why would he be in the building?"

Checking out the main Graves residence outside of NY, they find him tied up/in a very embarassing position, surrounded by a multitude of children. Turns out he has taken care of them while their usual caregivers are sick/out of the country/not available for some reason (and house elves just aren't enough to watch over a rowdy group of kids).

The kids could be his own or his nieces/nephews.