After the ship docks in the Spanish resort of Alicante, Donna, claiming a life-changing illness, boards with her friend Bernie. As the festive voyage begins, Donna charms fellow passenger Gary and visits a remote monastery, where she meets a mysterious priest and an enigmatic nun, but the holiday cheer is lost when Bernie is found dead. Meanwhile, the recently sacked Jack is lying low, but the murder draws Kate back to him and, with Jamil's help, the two might finally rekindle their romance.