A Mother's Desperate Plea
Harry Potter and the Half-Blood PrinceNarcissa Malfoy, fearing for Draco's life, forces Snape to make an Unbreakable Vow to protect and assist her son.
increasing
Bearing strength in each event
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The Visit to Spinner's End

The Plea
The Desperation
Narcissa Malfoy, terrified for her son Draco, goes to Severus Snape's house. She begs him to help Draco, who has been given a dangerous mission by Lord Voldemort.
The Request
Narcissa asks Snape to make an Unbreakable Vow to protect Draco and complete the mission if he fails. Snape hesitates but agrees.
The Vow
Bellatrix Lestrange acts as the Bonder. Snape swears to watch over Draco, protect him, and carry out the Dark Lord's orders. The vow binds him to a course that will lead to Dumbledore's death.
The Year of Anxiety

The Waiting
The Fear
Narcissa is constantly worried about Draco. She cannot contact him easily. She trusts Snape to keep his promise, but she is on edge.
The Support
Narcissa's love for her son is her driving force. She is willing to do anything to save him. Her maternal love is a powerful motivator.
The Outcome
Snape ultimately fulfills the vow by killing Dumbledore. Draco is spared from having to commit murder. Narcissa's plea saves her son's soul, but at a great cost.
early July, before the start of term
throughout the school year, from September to June