"O treachery! Fly, good Fleance, fly, fly, fly! Thou may'st revenge "
Ey, you will not get away!
In this part, Banquo and his son Fleance had left off to walk, Banquo had taken his horse and started walking with Flenace when a murder had stopped them.
In this part, one of the murderes had committed his mission and stabbed Banquo and he was left on the floor dying when he turned to look at his son to scream and tell him to run away and seek revenge.
In this part, Fleance is off running away avoiding to get killed since he was next, while his father laid dead in the floor and the murder just a ran away too but in opposite directions to warn Macbeth that Fleance had run away after his father's death.