2x10 - Bonanza

Gunnar Borgstrom is the leader of a vicious band called the Commancheros. They burn houses, kill people and steal anything of value. When the Commancheros get to Nevada, Gunnar decides to visit his relatives, the Cartwrights. Meanwhile the gang capture Little Joe and his girlfriend. When Gunnar returns to the gang, he has no idea who Joe is because he'd never met his nephew before.