The reason I have contacted you is because I believe you to be a mafioso who, despite belonging to a faction that I am at war with, is at least clear as to whose side you are on.
 
According to information I have received (from someone who shall remain forever nameless) there is a member of your team who does not fully share your objectives. It was this "widow's son" that Obi was trying to investigate on the night he was killed and it is his (or her) identity that I can disclose to you.
 
However, as a good student (I am sure you are well informed enough to be able to verify my identity from these words "I am now off to whine in a corner" in my second post in the thread) I will require information in exchange. 
 
Why am I doing this? It is not in my interests to see the Ministry, the Death Eaters or the Slytherins become too powerful and besides, the more useful I am, the less incentive you have to kill me.
 
I look forward to hearing your reply...
 
Finally, keep this PM entirely secret, you never know who you can trust in this game...