Insurance

I don't really have any experience with insurance, but the subject interests me, the way companies use statistics to calculate odds. (A bit like bookies!) I love the film noir Double Indemnity, which is about insurance salesman Fred MacMurray (intriguingly cast against affable type) scheming with femme fatale Barbara Stanwyck to sell her husband a big policy then murder him and get a big payoff, without arousing the suspicion of Edward G. Robinson, company investigator and MacMurray's friend.  It all turns out badly in the end, of course, but in an unpredictable way.

The script, adapted from James Cain's novel by detective novelist Raymond Chandler, has lots of great dialogue.  Like the best film noirs, it makes good use of Los Angeles locations.  In the scene where the husband gets killed, the camera sticks to a closeup of a clearly turned-on Stanwyck.  Really chilling stuff.  This was just Billy Wilder's third movie, but he was already an expert director!  He originally filmed an extra scene showing MacMurray's execution, but he cut it because it wasn't needed.  That's confidence.