Tasked with arranging his brother Max's Rune Ceremony, Alex decides this would be the perfect opportunity for his family to get to know Magnus. But with tensions flying among the different Shadowhunters, Max's big event quickly becomes an evening where they all must face their biggest fears.

Meanwhile, Simon makes a bold move as Isabelle finds an unlikely new ally.

The New York Institute is under attack as Valentine's plan for The Soul Sword is getting dangerously close to coming to fruition. The Shadowhunters must act fast to save their loved ones and the rest of the Downworld. Meanwhile, some of the Downworlders have their own plan to stop Valentine and their target is Clary.