Folie à Deux never shows us this TV movie, perhaps because that would be funny and interesting, two qualities the film abhors. But it got me thinking.

“Folie à Deux” does neither. Taking a cue from the last scene of “Joker” — a psych evaluation where Arthur hears Frank Sinatra’s “That’s Life” in his head and starts to sing along — the film is basically one long drawn-out courtroom drama, interrupted by musical numbers (old standards, most of them sung in Arthur’s head).