"Final Ransom" is a very good episode of "Barnaby Jones", though the ending wasn't completely satisfying.
The guest villain is Doyle, played wonderfully by Gary Lockwood. Lockwood had already been on several previous episodes of the series and always seemed to play the most vicious and interesting criminals.
The story begins with Doyle phoning Mr. Bentley to say that he'll return his kidnapped daughter...for $10,000. Now here's the kicker...the child had been kidnapped a decade earlier! So, either Doyle was lying and taking advantage of a grieving family OR Doyle somehow was unavailable to ransom off the kid...which turns out to be the case, as he was arrested for a different crime!
As far as the girl knows, her parents are her biological parents. But, in reality, her mother was Doyle's accomplice...and when she didn't hear from him, she decided to raise the child herself. Little does she realize that not telling her daughter and husband will result in major tragedy.
This is one of the more heart-wrenching and effective episodes. Jedidiah (Mark Shera) is better here in hid fifth episode, though I do wonder why Barnaby told Jedidiah to phone the police while Barnaby gives chase at the end! But that didn't bother me. What bothered me was the big confrontation scene between Doyle and the faux mother...it was badly done. See it and see what I mean. The same, by the way, can be said about Barnaby's final comment, which, in hindsight, was pretty dumb....and I agree with Jedidiah's assessment of the new family.