Snape invites Narcissa Malfoy and reluctant Bellatrix Lestrange them inside his house at SPINNERS END. Narcissa is frantic for Snape's help. But Bellatrix's distrusts Snape's true loyalties. Snape invites Bellatrix to clear the tension by asking him whatever she wants. Snape frankly answers her questions about his role as a Death Eater and proclaims his loyalty to the Dark Lord. Meanwhile there is a short scene with wormtail quite non significant. When Narcissa finally entreat es Snape for help, he finds that she's worried about her son, Draco, and the task Voldemort has required him to accomplish. Snape makes an Unbreakable Vow with Narcissa, promising that he will help Draco on his mission and protect him.
"THIS SCENE OR MAY BE A PART OF THE BOOK CLEARLY EXPLAINS HOW FAR SNAPE GETS TO FULFILL DUMBLEDORE'S ORDERS AND HE MAKES THE UNBREAKABLE VOW MAKING HIM A MAN OF CHARACTER"