She visited him to see if he knew what the Dark Lord wanted her son Draco to do && if the Dark Lord wanted Snape to carry on the task if Draco failed also she wanted Snape to make the Unbreakable Vow && help Draco so he would not be hurt.
In Harry Potter and the Half-Blood Prince, Severus Snape and Narcissa Malfoy performed the Unbreakable Vow. This is the ultimate magical promise, as if Snape chose to break this promise, he would die. Snape promised whilst holding hands with Narcissa and with the Bonder (witness) Bellatrix Lestrange, that he would assist Draco Malfoy in his task of killing Albus Dumbledore if Malfoy struggles or is in danger of failing. Snape obliged willingly, as Dumbledore and Snape has already planned Dumbledore's death.
Voldemort and his Death Eaters. He used to hate Severus Snape before discovering he was on the good side. He used to hate the Malfoy's before they changed sides and before Narcissa saved his life.
It begins when Snape and Yaxley meet up and go to see Narcissa Malfoy. When it goes to Harry, he is still at the Dursley's, preparing to leave for the last time.
Albus Dumbledore was killed by Severus Snape. Although Dumbledore, who was dying anyway, had already arranged for Snape to kill him so that Draco Malfoy wouldn't have to and so that the Elder wand would not change masters. However, as Draco disarmed Dumbledore shortly before his death that part of the plan did not work.
Snape was never really close enough to Lucius Malfoy to be considered "working with him" but if you mean is he evil then no. Sure Snape had his fair share of fascination and skill with the Dark Arts but he is a good man working truly with Albus Dumbledore!
The Unbreakable vow the unbreakable vow which is when snape makes the vow if he breaks it he dies
In Harry Potter and the Half-Blood Prince, Severus Snape and Narcissa Malfoy performed the Unbreakable Vow. This is the ultimate magical promise, as if Snape chose to break this promise, he would die. Snape promised whilst holding hands with Narcissa and with the Bonder (witness) Bellatrix Lestrange, that he would assist Draco Malfoy in his task of killing Albus Dumbledore if Malfoy struggles or is in danger of failing. Snape obliged willingly, as Dumbledore and Snape has already planned Dumbledore's death.
Voldemort and his Death Eaters. He used to hate Severus Snape before discovering he was on the good side. He used to hate the Malfoy's before they changed sides and before Narcissa saved his life.
It begins when Snape and Yaxley meet up and go to see Narcissa Malfoy. When it goes to Harry, he is still at the Dursley's, preparing to leave for the last time.
During the school year, they are at Hogwarts. When school is out, Malfoy lives with his family at Malfoy Manor while Snape lives in a house on Spinner's End.
Albus Dumbledore was killed by Severus Snape. Although Dumbledore, who was dying anyway, had already arranged for Snape to kill him so that Draco Malfoy wouldn't have to and so that the Elder wand would not change masters. However, as Draco disarmed Dumbledore shortly before his death that part of the plan did not work.
This is a very broad question, and not worded correctly. Severus Snape killed Albus Dumbledore in the end of the sixth book. Dumbledore had asked Snape to kill him, to save Draco Malfoy's soul because of the Unbreakable Vow that Narcissa Malfoy made Snape take in the beginning of the sixth book since Voldemort had ordered Draco to kill Dumbledore.
(WARNING: SPOILERS) Rowling never makes it expressly clear in any of her books. However, it is likely that Snape already knew that he would be the one to kill Dumbledore. This, after all, is what Narcissa pleads him to promise: That Snape will watch over Draco, that he will intervene if necessary to secure his saftey, and that, if Draco fails to kill Dumbledore, that Snape will do it for him. Now, obviously Snape knows, since he is on Dumbledore's side, that Dumbledore wouldn't ever hurt Draco or put him in harm's way. So that he could honestly promise Narcissa with little problem. Also, because he promises to kill Dumbledore should Draco fail, we can assume that he has already had the conversation with Dumbledore that deals with Snape bringing about Dumbledore's death when the time comes. This allows him to promise truthfully that he will kill Dumbledore. Snape also has a certain prejudice in Malfoy's favor, since he happens to be an exemplary Slytherin student and is good at potions (though this may well be due to grade inflation). Of course he promises to keep his favorite student safe: but what Narcissa doesn't know is that Snape is not agreeing to protect Draco from Dumbledore and the Order; rather, he's agreeing to protect Draco from Voldemort and from bringing about his own downfall. We see Draco's attempts to throw Snape off his track and to get him off of his back throughout the sixth novel, but know that Snape ultimately succeeds and keeps Draco (as) safe (as he can) from "The Dark Lord".
No, Severus Snape is.
Severus Snape or Draco Malfoy
No, Severus Snape did.
The introduction describes the Black sisters Narcissa Malfoy and Bellatrix Lestrange visiting Severus Snape's house. Voldemort has ordered Draco Malfoy, Narcissa's son, to kill Albus Dumbledore, a task which he knows is impossible. It is a punishment for Lucius Malfoy, Draco's father, failing to collect the prophecy from the Department of Mysteries in the Ministry of Magic at the end of Harry Potter and the Order of the Phoenix. The conversation between Narcissa, Bellatrix and Severus begins with Narcissa explaining the situation to Severus. Bellatrix cuts in accusing Severus of disloyalty. She then lists questions that she believes Severus cannot answer, which would indicate his guilt. However, he answers all of them quite easily, so she is left without proof. Narcissa asks him to take care of Draco and guide him in his task, and to complete it if Draco cannot. Severus agrees, but Bellatrix asks how they can be sure he will truly do so. Severus then makes an Unbreakable Vow to Narcissa.