When her father disappears into Monaco city to escape his massive debt, a girl must trace him down or face an arranged marriage with the loan shark

Great setup. We need to know more about the main character: strength, flaw.

The structure is not dissimilar to WINTER'S BONE, where the daughter needs to find her father against a ticking clock, or else...

That movie had a great mid point that changed its direction - and the goal. I feel this concept needs a good mid point reversal too. It may be hard sustaining a full second act without it. What is her insight? Something that links her personally to what happened to her dad?

I agree with the others.

The punishment for failure is very interesting and original. I like it.

I'm tempted to say we need to know more about the father. But really, if we read into his actions. He has fled his debt and left it for his daughter. That really sums him up well. Selfish and cowardly. He has plenty of room to arc.

But we definitely need to know a little but about the girl. What makes her the right or wrong person for the job. Does she have a certain skill set that could help like Liam Neeson's character in Taken? Even better if you hinted at how she feels towards her wayward father.

I'd read the script/watch the movie.

When her father disappears into Monaco city to escape his massive debt, a girl must trace him down or face an arranged marriage with the loan shark

Hi trystla! I gagree it's pretty good, but I think it can be more intriguing, enticing, and therefore, more effective. I would find a strong adjective to describe the father character as well as the daughter, a character flaw that will obviously arc throughout the story, but also display irony as the story progresses. If he's spineless, he may later have to become tough and stand up to the loan shark to get his daughter back- something like that. Same with her; if she was incorrigible towards him, she'll have to overcome their differences in order to put his safety before her own in finding him, and force them to work as a team in order to get out of the predicament. That said, a new logline might read:

"When her GUTLESS father disappears in Monaco to escape his massive debt, his REBELLIOUS daughter must track him down or face an FORCED marriage with the SLEAZY loan shark."

I think it's a cool concept, too. Good job!