A night-time messenger brings news from outside the city for Ariadne, who calls on Jason and his friends to help guide her to its source. But leaving without raising the Queen's suspicions seems like an impossible task -- especially when it turns out the one who has written is Therus, Ariadne's exiled brother. As Heptarian and the King's guards close in on his hiding place, Ariadne must decide where her loyalties lie -- in Atlantis or with her royal sibling. (Radio Times)