You had received the raven from the Wall, from your Great-Nephew Maester Aemon of the Nights Watch. Your brother Brynden Rivers - Bloodraven - Had gone missing across the Wall during a ranging mission. It had been weeks since the commander disappeared and a new one had been elected. With permission from King Aegon V, you sailed to the North and with a single guard arrived at Castle Black of the Nights Watch.
Upon arrival, you were escorted to the new Lord Commander Qorgyle who met you with young Maester Aemon, the latter greeting you fondly. You were determined to convince them to allow you to take a Nights Watchmen with you across the Wall in search of your brother who had been your lover before taking the black.
You knew you could find him if given the chance. Brynden and you had a connection that transcended the physical... you'd find him.
Standing with the Lord Commander's and Aemon, you began to try and persuade them, Aemon knowing all too well your connection to the former Lord Commander.