2x11 - The Legend of Prince Valiant

The trio's mission to aid the town of Rheged in its reconstruction efforts leads to a joyful reunion between Arn and his old friend Harold. The pair grows closer than ever as Arn meets Harold's family and hears Harold's dream of Arn's future knighthood. Things take a horrible turn when Harold's old deception comes back to haunt him. The resulting tragedy infects Arn with a violent desire for revenge that not even Valiant and Rowanne can talk him out of.