Complex sentence: Meanwhile, Brennan goes to see Russ and explains she never told their father that Booth wouldn't arrest Russ, then implores Mrs. Julian, the prosecutor on her father's case, who has named Russ as a material witness, to let Russ go.
Split into simpler sentences: Meanwhile, Brennan goes to see Russ and explains she never told their father that Booth wouldn't arrest Russ. She implores Mrs. Julian, the prosecutor on her father's case, who has named Russ as a material witness, to let Russ go.