He attempted to kill Dumbledore, but Dumbledore tried to convince Draco not to perform the task. Draco said that he had no choice. Otherwise, Lord Voldemort would murder him and his family. Dumbledore told Draco that he shouldn't do this, and that Draco was not a killer.
It might be argued that Draco was afraid of Dumbledore, and that is why he wouldn't cast the curse. Dumbledore even suggested that Draco was afraid to act until he had some support.
So, during the summer between his fifth and sixth years at Hogwarts, Draco Malfoy was tasked with the assassination of Albus Dumbledore to restore his family to Voldemort's good graces. Also at this time, Draco was branded with the Dark Mark. This killed two birds with one stone for Voldemort.
At the end of Book 6, “Half-Blood Prince,” Draco disarmed Dumbledore before Snape killed Dumbledore. “And that meant he conquered him, even though Dumbledore was very weak at the time, he was very ill. He was on the point of collapse when it happened,” Rowling said.
Three times. All quotes from the Half-Blood Prince.
Also, Dumbledore knows Harry was mistreated because he told Harry “you had suffered. I knew you would when I left you on your aunt and uncle's doorstep. I knew I was condemning you to ten dark and difficult years.” He even says to the Dursleys, “he has known nothing but neglect and often cruelty at your hands.” And “…
Snape saved Draco, and having realised that Harry got a hold of the old textbook, he punished Harry with a multitude of detentions for nearly killing Malfoy. Harry, despite disliking Malfoy, did not truly want to harm Malfoy to such an extent, and was both horrified and guilt-ridden by using the curse against him.
Lucius and Draco's crimes were forgiven due to their abandonment of Voldemort and his cause and Narcissa's lie to the Dark Lord that saved Harry Potter's life in the Forbidden Forest in the Battle of Hogwarts. None of them served time in Azkaban.
Malfoy spots Harry and casts a Cruciatus curse; Harry, defending himself, using the Half-Blood Prince's Sectumsempra spell without knowing its effects. To his horror, it gashes Draco's face and chest, spilling his blood everywhere. Moaning Myrtle flies off, screaming.
Voldemort intentionally made six Horcruxes, but when he used Avada Kedavra on Harry, he unintentionally created a seventh Horcrux. Instead of dying, Lily's love for Harry created a counter 'curse' known as Sacrificial Protection and saved Harry.
Furious at the world that seemed suddenly to have turned on his father, Draco accepted full membership of the Death Eaters and agreed to perform the murder Voldemort ordered.
Narcissa Malfoy's Very Dangerous Lie
But she was also a mother, which meant she was willing to risk everything to make sure her son was safe. When Harry survived Voldemort's Killing Curse for the second time, Narcissa pretended he was dead so she could get to Draco.
Voldemort intended Draco to die in the attempt to kill Dumbledore so that Lucius would be punished for his failure to retrieve the prophecy from the Ministry of Magic. Although Draco does not directly take part in Harry's final confrontation with Voldemort, he influences its outcome.
Despite being a valued Death Eater in the days before Voldemort fell following his attack on baby Harry, Lucius stumbled out of favor with the Dark Lord when he squandered Riddle's diary (secretly a horcrux) in Chamber of Secrets and failed to obtain the prophecy in Order of the Phoenix.
Draco Malfoy - Voldemort
In this game, it becomes clear that Draco Malfoy's Boggart is Lord Voldemort. Draco's fear of Voldemort likely comes from different reasons than others have. Most fear Voldemort taking over the world. Draco fears Voldemort intimidating and manipulating the Malfoy family.
At the end of the series, Dumbledore admits to Harry that power is his ultimate weakness. He was always conscious of it, and he feared that power had the potential to corrupt him beyond help. That's why he never accepted the Ministry of Magic position even after it was offered several times.
First of all, Draco cries when the bird comes back dead.
Well, Harry and Ron only figured out it was a basilisk when they found the torn piece of paper in Hermione's petrified hand. Everyone assumed that Hermione was the one who figured it out, but a Tumblr user named Indie-band theorizes that Draco might have had a helping hand in the discovery!
His tears were due to the fact that since the bird had died, he had failed once more to repair the Vanishing Cabinets. Draco needed to repair them in order to give the Death Eaters a safe way to infiltrate Hogwarts. Failure meant death, Voldemort had made that very clear.
Rowling commented that "The moment Draco got what he thought he wanted, to become a Death Eater, and given a mission by Lord Voldemort, as he did in Harry Potter and the Half-Blood Prince, reality finally hit him" because his dream was "so very different".
Because he and his family defected from the Death Eaters they were pardoned for their crimes after Voldemort's final defeat and did not serve a stint in Azkaban. He and Narcissa later had a grandson, Scorpius Malfoy, after Draco married Astoria Greengrass.
The Slytherin family, like many of the pure-blood families, had some relation to many other families in the wizarding world. The Peverells, Gaunts, Blacks, Malfoys, Potters, Weasleys, Prewetts, and other families are all linked to one another through bloodlines and intermarriage.
Vulnera Sanentur was the song-like incantation of a healing spell and counter-curse to the Sectumsempra Spell, which was invented by Severus Snape.
Out of desperation, Harry used it on Malfoy, as Malfoy was preparing to hit Harry with the Cruciatus curse. It apparently causes the caster's wand to act as a very long knife, thus resulting in the target getting huge cuts across their body.
The Emerald Potion, also known as the Drink of Despair, is a mysterious potion which induces fear, delirium, and extreme thirst. According to Dumbledore, the potion cannot be penetrated by hand, vanished, parted, scooped up, siphoned away, transfigured, charmed, or otherwise made to change its nature in any way.