What was the main conflict amongst Baldwin and Mc Murdo?

Teddy Baldwin is the young and hotheaded brother who wants to marry Ettie and resents McMurdo getting in his way. He continually butts heads with McMurdo; however, he grudgingly accepts him, until his true identity is revealed. He tracks McMurdo to England and tries to kill him; instead, McMurdo/Douglas kills Baldwin in self-defense.