If you are having trouble formulating a concise log-line for your story, chances are your plot is suffering from DGD (Dramatic Grammar Deficiency), or - worse - that you are failing to grasp the emotional logic of what is actually going on as evidenced by the actions and interactions of the characters. If this is not the case, then basically what you have to do is, look at the beginning of the second act of your story. That is the main chunk of it. You imply Act 1 with your protagonist’s adjective of manner that contrasts them against the new world of Act 2 they have dived deep into. You also must imply the consequences of the protagonist failing in your log-line to make things not boring when you tell someone about it so they’ll want to know more.
That’s literally all there is to it.