Carlisle tries to reason with Aro insistent that the matter can be solved without the need to fight. Aro ponders upon his former friends word and calls Edward forward and reads his thoughts to discover that Renesmee is not an immortal child, but is half vampire and half human. Intrigued by the discovery, he calls the child, now identified as Renesmee forward. Bella along with a wolf and Emmett come forward with her. Aro is charmed as she shows him her history and nature.
Aro sternly turns his head towards Irina after realizing she was mistaken. Irina admits that the child she saw was smaller and apologizes for her mistake, taking full responsibility. Aro orders the execution of Irina, upon which Felix steps forward and unscrews her head off.
Tanya and Kate, distraught at the sudden and shocking death of their sister, immediately rush to attack, and it takes the work of the rest of the allies to control them. As they realize it was his plan to invoke a violent response, the Cullens and their supporters regain their control.
Aro suggests to Volturi that because Renesmee is unprecedented, she is unpredictable and therefore unsafe. He explains in this age of technology, only the known are safe and they know nothing of what Renesmee will become, therefore she should either come with Volturi or be executed here.
Suddenly, from the woods, Alice and Jasper stride forward into the clearing. Simon gritted his teeth as the thought that they both had escaped was crushed.
Alice steps near Aro attempts to show him she has seen the future and Renesmee poses no threat. However, in a blink, suddenly, Alice gasps in consternation as she realizes that no matter what she shows Aro, he has already decided on the future of the Cullens: they must be destroyed because they are a threat to his rule and he wants the talented individuals under his control. Alice gives an apologetic look to Simon and Jane then turns and gives Bella a surreptitious signal that it is time to take Renesmee to safety. Alice then turns and kicks Aro across the field indicating the start of war.
Grimly, Bella sets Renesmee on top of a wolf that speeds away, she turns to face the Volturi. Jane attempts to weaken Edward with her power and is frustrated when she realizes that Bella, with a satisfied smile, is protecting him with her shield.
Alice and Jasper being the closest were seized by the Volturi, which brings Carlisle flashing forward in loud protest. Shockingly, Aro intercepts Carlisle in mid-leap and decapitates him in one blow, and Caius then burns Carlisle's body. The Cullens and their allies are enraged at Carlisle's death, and a violent battle ensues between the allies and the Volturi, where there are many fatalities on each side.
Simon and Jane deliberately avoid a direct confrontation with Jasper and Alice and the same with them.
Seeing that Bella was shielding Emmett from Jane, while he fights with Demitri, Alec leaps at Bella and grapples her, breaking her concentration; Jane is then able to disable him with pain. Felix holds Emmett while Demitri decapitates him. Edward rushes to Bella's aid, throwing Alec to the ground and stomping on his throat, before ripping his head off.
An alpha kills a Volturi soldier and then charges at Jane, but cannot stand against Jane's pain illusions, making him helpless as Simon grabs him from behind and crushes his ribs completely in his arms.
A Volturi pursuer to gain ground against the wolf carrying Renesmee. But when he hears howl indicating the fall of alpha, it intercepts the leaping Volturi and decapitates him in mid-air, and hits the ground running with Renesmee still on his back.
The battle starts go badly for the Cullens and their allies; Bella is being overpowered by four Volturi, another Quileute falls and Edward is fighting a losing battle with Demitri. An ally of Culllens, Benjamin smashes his fist into the ground, causing the earth to crack open, revealing lava far below. Two of Bella's opponents fall into the crevasse and she is able to overpower the other two with her newborn strength. Simon noticing the danger he possessed rushed and punched him in the face.
Demitri shoves Edward down into the crevasse and turns away, only to see Edward has barely escaped death by clinging to the side; Edward leaps back out of the crevasse and kills Demitri. Esme claws desperately to keep from falling in as a Volturi clings to her back trying to kill her. A wolf comes to the aid of Esme, destroying the attacking Volturi, but falling to her own death into the lava below. Rosalie, enraged over her mates death, attacks Jane while protected by Bella. Unable to use her powers she understands that she has no chance of winning against multiple enemies, Jane turns and flees, but Rosalie leaps ahead of her, seizes Jane by the throat and throws her to a wolf, who gladly rips her head off.