How does Borden and Angier's feud begin?

Many magicians of that time took advantage of grieving people by using magical techniques to gain funds from the rich by claiming spiritual powers. Borden witnessed Angier doing this at Borden's grieving aunt's house one day, so Borden attended the next seance that Angier held and tried to expose him as a fake. Borden was kicked out. From that point forward, Angier vowed to follow Borden closely and ruin his career in any way possible.