The Note
Dear Mrs Narcissa Black Malfoy,
I would like to start this letter of by saying that only you can read the true contents of this letter. It is charmed to only reveal it's contents when you are alone. As soon as you are with your husband, Lord Malfoy, the letter will hide it's contents again. I am quite aware that you could tell him about the true letter but I would advise against that.
I am truly sorry for telling you this but Lord Voldemort will return (if I can't prevent it). If he does, your son will not be safe. This is why I have taken him- for his own safety.
As unbelievable as it sounds, I am from the future. Just before his sixth year, your son was forced into getting the dark mark. He was given the mission by Voldemort to kill Dumbledore. Your son tried but found that he could not kill another person. He wasn't killed for his failure because you went against Voldemort's orders and got someone else to kill Dumbledore. Your son was put into situations that no child should ever have to face due to the cowardice of Lucius Malfoy. At one point, he would have died if I hadn't intervened. It was for this reason that you lied to the Dark Lord for me- something which kept me alive and allowed me to vanquish Voldemort for good.
I am telling you this because I understand that you are no death eater. You don't want to kill people due to pureblood supremacy beliefs. You are doing it because you need to survive- because you are afraid. It's okay to be afraid and it's okay to need to help.
I have seen how much you love your son. I'm not keeping you from him. As soon as it is safe for you to be together, you can be.
Becoming a death eater ruined Draco's life after the war. People didn't trust him and everyone thought his son was Voldemort's son for some peculiar reason. I am certain that neither of you would want this.
If this letter doesn't convince you on its own, you should know that Voldemort is a half-blood. His real name is Tom Marvolo Riddle. His name is an anagram for 'I am Lord Voldemort". His father was a muggle and his mother was a member of the gaunt family.
You all left the final battle before it was over. You fled. Lucius did it because it was obvious Voldemort was loosing but you both did it because you didn't want to participate.
It isn't too late to start afresh. I know people that would help you and money and places to live aren't a problem. I'm also sure that Andromeda Tonks nee Black would help you out. Sirius Black shouldn't be too disinclined to help his older cousin either and I will put in a good word for you. Worst come to worst, I will help you with no hesitation, no questions asked. The suggestions of asking
I will leave you with some information about your future grandson. His name is Scorpius, as Draco wanted to carry on the Black family traditions.
Sincerely,
Harry James Potter