He's no longer sure it's the right thing to do, if he ever was. His father was arrested and while his mother pleaded with him not to take the Mark, he saw it in her eyes that she feared it was the only way to get Lucius home to them again. Draco had a duty to fulfil. His father's only heir, his father's only hope. And his father had always preached the importance of loyalty, of obedience, of being reliable and following through. Everyone needed to know that a Malfoy could and would get the job done.