Mass murder attack (by one
person, on at least four) at Hogwarts. One victim was explicitly
name-checked in JKR's Epilogue as alive and well at that time - which means one of three things: Only Mostly Dead, Reset Button, or He Just Didn't Care.
I don't think it's Reset Button this time - he already did that in Sluagh
Hermione apparently knows or suspects who's doing it, and has been trying to catch the killer - but this tends to put her right on the scene at the worst possible time. So she's just been busted as Suspect Number One.
I happen to know who the killer is supposed to be (not
Hermione, of course), and the culprit has scarcely even been mentioned and I'm not sure they made an on-page appearance. I really don't think that's playing fair with the reader.