Rupture: The End of Pure-Blood Frauds

Evangeline, a Muggle-born genius witch who spent three years laying Bruntia's highest-level Dark Magic Defense Array, is dismissed and divorced by her husband Lester, who wants to hand her position to his mistress Serena. She signs without hesitation and cuts off the array's magical supply.

Within three days the border barrier collapses entirely; Dark Wizards and creatures flood in, and Serena abandons her team and flees.