Grindelwald became rather fond of Graves while he was holding him captive. Post-film, after he escapes from prison, every now and then he hears information that is vital for the cases Graves is working on. He begins to drop him a note now and then. One day, Grindelwald hears something that, if Graves doesn't know, the auror (oh, and the investigative team, Grindelwald supposes) could get killed. So, he decides to deliver it in person. He disguises himself and infiltrates MACUSA's company ball.
Graves has no idea the handsome man who asks him to dance is Grindelwald until his dancing partner begins to call him the same pet names Grindelwald used with him and telling him information about the trafficking ring he's been investigating. But, as Grindelwald informs him, exposing the other wizard could result in the death of most if not all of the guests, so Graves just keeps on dancing.
Graves/Grindelwald- Dance
Graves has no idea the handsome man who asks him to dance is Grindelwald until his dancing partner begins to call him the same pet names Grindelwald used with him and telling him information about the trafficking ring he's been investigating. But, as Grindelwald informs him, exposing the other wizard could result in the death of most if not all of the guests, so Graves just keeps on dancing.
Please no noncon between Graves and Grindelwald.