Some ponies just shouldn't have kids together...

After a few events during Sweet and Elite were taken too far, the latest arguments between Rarity and Prince Blueblood are about their filly. The two are perfectly content with ignoring each other. Despite this, this plan doesn't work out quite like they thought it would when it is revealed that it isn't just a few jilted mares that aren't fans of Blueblood. The entire Blueblood family is being targeted by a secret circle who wants to see the downfall of the bloodline. Starting with the newest addition.
Can two ponies who hate each others guts work together to save their filly?