Husayn's most important task would become clear. Mullá Husayn and Qambar-Ali left Maku carrying copies of significant works of the Báb which had been written during his stay in Maku, which they shared with Bábís during their journey to Mazandaran. A few days after Mullá Husayn departed from Maku, he received news that by order of the Prime Minister the Báb was to be transferred to the castle of Chehriq. Mazandaran On his way to Mazandaran, he stopped briefly in towns with resident Bábis, sharing news of the Báb and encouraging the Bábis, who were facing increasing public opposition. In Tehran he again had a chance to meet with Baháʼu'lláh, who encouraged him in turn. Mullá Husayn was received on his arrival in Barforush, Mazandaran, by Quddús, the 18th Letter of the Living. Although the two had met previously, they had never spent much time together and their last interaction had been tinged with Mullá Husayn's disappointment when Quddús was chosen to accompany the Báb on pilgrimage rather than himself. During his stay in Barforush he was a guest in the house of Quddús and was able to consort with the large number of converts and admirers Quddús had in that city. Nabil reports that Mullá Husayn shared with Quddús the Báb's promise that in Mazandaran he would find a "hidden treasure which shall be revealed to you, a treasure which will unveil to your eyes the character of the task you are destined to perform." After reading some of the writings of Quddús, Mullá Husayn became convinced that Quddús himself was the hidden treasure that the Báb had referred to. Previously many of the Bábís had thought of Mullá Husayn as the most significant figure in the movement after Quddús; after this interaction Mullá Husayn constantly deferred to Quddús, going so far as to serve his meals and obey his instructions with a reverence previously reserved for those of the Báb. Quddús's role as the chief of the Letters of the Living was later confirmed by the Báb. In Barforush Mullá Husayn engaged the leading Muslim cleric of the city in a public debate with the goal of either converting him or convincing him to reduce his public denunciation of the Bábis. After failing to convince him, Mullá Husayn–at the instruction of Quddús–left Barfurush to return to Mashhad once again. The Bábíyyih of Mashhad In Mashhad, following the instructions