On May 1st, As a punishment to King Arthur, Merlin made him give 40 babies including his own evil born son the Death Penalty by throwing them on a boat and sending them out to sea to die because King Arthur had a son with his own sister which is a crime.
Unexpectedly, Nyneve comes back for Mordred to take him to lothian, but they have to travel through the forest perilous and have to survive through the night revealing some of Nyneves magical powers.
Not long after Nyneve takes Mordred to lothian, he decides to leave and go to visit his father on his 16th birthday AKA May Day. After meeting his father, soon after Mordred wants to ask his Father if he can go on his own quest alone.
Gone But Not GoNe
Trying to go against his fate, Mordred tries to give up his soul to possible change his evil feelings about his father, but in order to do that Mordred has to give his soul to someone he trusts. Nyneve is dead so the only person he really has is King Arthur... During the ritual Mordreds soul is released and as its sitting there, the raven swoops down and snatches up his soul stealing it from the both of them leaving mordred emotionless.
Mordred realizing his fate, he now knows that he must kill his father unfortunately. They both run at each other with their swords, King Arthurs driving right through Mordreds stomach, and mordred pushes through driving his sword through Arthurs head killing him instantly.
Now that they are both dead, Arthur will be taken to a magical island to heal as said he will come back one day and that he is never gone. Also mordred continues to live on through the raven because the raven took his sould and left his body.