Three vampires step out of the woods – Laurent, James, and Victoria. Unlike the Cullens, they appear to be wild and more predator-like. They approach the Cullens, and Laurent greets them in a friendly manner. Carlisle introduces his family – and includes Bella among them.
Laurent is surprised to hear that the Cullens maintain a permanent home in Forks, and Carlisle offers that they should come visit the Cullen home.
All of a sudden, James gets a whiff of Bella. No one had mentioned that she was human.
A swift rigidity fell on all of them as James lurched one step forward into a crouch. Edward bared his teeth, crouching in defense, a feral snarl ripping from his throat. […] it was the single most menacing thing I had ever heard. (18.27)
Though Laurent is surprised that the Cullens have "brought a snack" (18.30), he's not in attack-mode. Carlisle says that Bella is with them. James steps back, but he's clearly still interested in Bella.
Calmly, Carlisle offers to show Laurent, James, and Victoria his home, and tells Edward, Alice, and Emmett to take Bella home.
In the car, Edward is determined to get Bella out of Forks as quickly as possible, saying, "I saw his mind. Tracking is [James's] passion, his obsession – he wants [Bella], Alice – her specifically. He begins the hunt tonight" (18.69).
Worried that James will follow Bella's scent to Charlie's house, Bella hatches a plan to lead James away from her father:
"You take me back [to Charlie's house]. I tell my dad I want to go home to Phoenix. I pack my bags. We wait till this tracker is watching, and then we run. He'll follow us and leave Charlie alone. Charlie won't call the FBI on your family." (18.96)
After leaving Charlie's house, Alice and Jasper will take Bella to Phoenix, while Edward leads James on a wild-goose chase in the opposite direction.
Edward hesitantly agrees to the plan, angry and worried that he'll have to leave Bella's side.