Dear Bureau,
I would like to inform you of an assassination attempt by the Burgundy Intelligence Service, which is scheduled to take place in Washington D.C on Month X Day Y this year.
The target of the assassination is the US Attorney General. As this is a federal crime and plotted by a foreign intelligence service, I hereby report it to the FBI.
The agent in charge of the plot is Mr. X, who happens to be my penfriend. His cover is a security guard in the Y building across the street from the Department of Justice. He told me about this in one of his letters to me.
I hope this letter will be forwarded to the National Security Branch of the FBI and you can contact me anytime by the phone number of 1234567.
Sincerely Yours,
Hua Li