The only official relations described with the Muggle world are between the Minister for Magic and the Muggle Prime Minister. In "Harry Potter and the Half-Blood Prince" it is revealed that the Minister for Magic privately introduces himself to each new Prime Minister and briefs him on the important matters of the Magical world. There is a magical painting in the Prime Minister's office that notifies him of such visits, and a fireplace that is connected to the Floo Network, which is how the Minister for Magic travels to 10 Downing Street. Minister for Magic Cornelius Fudge informed the Prime Minister of the escape of Sirius Black. Fudge also informed the Prime Minister that several problems he was facing were rooted in the war against Voldemort, and that the Prime Minister's new secretary Kingsley Shacklebolt was an Auror. Fudge treats the Muggle Prime Minister with condescension, and the Muggle Prime Minister is often frustrated by the Minister for Magic.