Overview: It's the day of reckoning, as Grimaud vows to kill the Musketeers in a series of savage co-ordinated attacks and puts Feron to the ultimate test in his bid for power. The furious battle for survival sparks a series of revelations that threaten to destroy Paris. Before the day is out, a hero falls, there’s a traitor on the rise and the Musketeers will be changed forever.