Complex sentence: Since she refuses to go with him, he binds and gags her and she becomes Frank's reluctant companion, while he tries to find out who is trying to kill him; and he tracks down his old associates for help.
Split into simpler sentences: Since she refuses to go with him, he binds and gags her. She becomes Frank's reluctant companion while he tries to find out who is trying to kill him; and he tracks down his old associates for help.