A bogus spiritualist and an amateur actor hope to con a wealthy woman out of $10,000 by locating her sole heir ? a nephew given up for adoption under shady circumstances ? but find they are in deep water as the nephew turns out to be a kidnapper who?d rather not be found

This one is intriguing. But it doesn’t quite highlight the stakes enough. The nephew doesn’t want to be found right? So is he himself a much harder core criminal, meaning the fake spiritualist and the actor have bitten off more than they can chew and now are faced with life threatening retaliation? Or perhaps the nephew is even more of a cunning criminal than they are, and he outwits them at their own game. Maybe the nephew is an undercover cop and they blow his cover. There are tons of ways this could go. I think some hint of the direction of your movie will be helpful in the logline.

>>IMDB one-liners... are used to sell to an audience whereas a logline is used to sell to a producer

An important distinction. And some of the IMDB one-liners are poorly written; I wonder where they get them.

I'd never call those IMDB one-liners a logline. VERY different purpose! The one-liners are used to sell to an audience whereas a logline is used to sell to a producer. That's my approach anyway.

No problem with me.
Must ask Alfred Hitchcock (1899-1980), Slingink, because the first one is genuine!

Sorry, I hope didn't offend!
I meant the components of the logline more so than their arrangement.
What is interesting is that the IMDB logline is quite different:

"Lighthearted suspense film about a phony psychic/con artist and her taxi driver/private investigator boyfriend who encounter a pair of serial kidnappers while trailing a missing heir in California."

Hi Slingink,

What one do you find terrible?

"to con " means " to swindle". In 1976, we still put "to" in front of an infinitive.

I find the second flat, terrible; and the first terrific, full a humor, with a great hook!

You should watch this movie. This is a very good one by a great master.

Nevermind. Just realized that this is an existing film. Never saw it.
Terrible logline.

I think you could up the ante. $10k is barely worth the risk.
How is it a con? If it were a con, it would seem one of them would try to impersonate the nephew.
Why are they in deep water with a kidnapper? He?s not going to nap them, is he?

I can?t even begin to formulate a logline, as I have no idea what the story might be. What?s their goal? Do they spend Act 2 searching for the nephew? Or do they spend Act 2 escaping from the nephew?

This logline is 51 words long.

Here is the 27 words version of a screenwriting guru ( http://www.crackingyarns.com.au/2010/03/25/the-most-important-27-words-a-screenwriter-will-ever-write/ ):

"A bogus spiritualist and an amateur actor can wangle $10,000 if they locate an heiress?s sole beneficiary, but discover he?s a kidnapper who wants to remain hidden."

Nice isn't it? Would you be able to do better?