The Ladder of Prayers
The Zohar tells of a dove that makes its nest outside the palace of the Mashiach in Paradise.  The palace of the Mashiach is also known as the "Bird's Nest." 
"The Ladder of Prayers" builds on the earlier legendary accounts of the golden dove, reporting an attempt by the Baal Shem Tov to ascend on the ladder of prayers of his Chasidim into Paradise to capture the dove.  The Besht believes that if he can use his mystical powers to snatch the miraculous bird of the Mashiach, he can cause the Mashiach to follow it, since the Mashiach cannot bear to be apart from its enchanting song.  The Besht fails at the last moment because the ladder of prayers of his talmidim, on which he has ascended, collapses.  The failure of the Baal Shem's Chasidim to provide the spiritual support needed for this great endeavor, as symbolized by the collapsed of their ladder of prayers, is offered as the reason for the failure to bring the Mashiach in their generation.  Thus the tale illustrates the interdependency of the tzaddik and his Chasidim. 
This attempt to capture the golden dove and its failure marks one of the basic types of mystical tales - those concerning an attempt to hasten the coming of the Mashiach.  Several such tales are found in the Talmud.  Subsequently such tales are found in virtually every generation, explaining that there is a potential Mashiach who, had all gone well, would have served as Mashiach ben Yosef, preparing the way for Mashiach ben David, the Baal Shem, however, he ascends directly to the palace of the Mashiach ben David, determined to initiate the End of Days.