The Vatican seeks the help of the Doctor as a translation of a book called the Veritas has emerged, and everyone that has ever read it has taken their own life, as supposedly it holds the ultimate truth of life. The Doctor accepts and seeks the help of Nardole and Bill to uncover the secrets of the book in the Vatican secret library of blasphemy, the Haereticum. Shortly they discover that an online translation has been leaked, and the message has spread around the globe and is causing mayhem. Can the Doctor withstand the ultimate truth, and is this a part of a much bigger scheme that the TARDIS team has to fight?
—Jose Benavides