Agatha is one of the templars under Knight-Commander Meredith, who believes that the duty of a templar should not go beyond the hunting of apostates.
Mettin enlists the aid of Hawke in dealing with citizens harboring apostates. Unlike Ser Mettin, she does not hold extreme views about her duties. If Hawke chooses to side with Mettin regarding on how to deal with the mage sympathizers, Hawke will be forced to kill Agatha. Otherwise, Hawke will fight Mettin alongside Ser Agatha.