One minute, Russell Napolitano is sitting pretty as L.A.’s charismatic mayor, a man on the verge of remaking a great world city.

Not a few days later he’s stumbling at gunpoint through darkened Venice streets -- no shoes, no cell phone, his good friend murdered, his perhaps-lover abducted, his political career in shambles, his very life at risk.

How did Napolitano sink so far so fast? And how can we take such a preposterously sudden turnaround and make it not only believable but compelling?

With that challenge in mind, I exercised my producer’s prerogative this week and wrote the latest installment of our collaborative script “Right of Way” myself. We had other submissions, but our story is at a critical juncture as it approaches its midpoint, and I had a definite idea about what I thought it needed.

First of all, I wanted Celeste’s predicament to grow murkier than ever. The mayor’s good friend and possible lover had been kidnapped several pages earlier, and Napolitano had made the dubious decision to try to get her back through unofficial channels.

If he succeeded, the story’s momentum would come grinding to a halt. Where could we go next that wouldn’t make her abduction and rescue seem gratuitous?

If he alerted the authorities, we’d have the basis for a conventional hostage rescue drama, with our protagonist, the mayor, getting pushed aside as the pros take over the job and drive the story.

No, what works best is for Napolitano to jump in and botch things so severely that he’ll have to spend the rest of the script trying to extract himself from the cavernous hole he’s dug.

And in pages 47-50, that’s just what he does, dealing with a kidnapper who, like the mayor himself, is by turns sharp as a tack and hopelessly inept.

We can believe Napolitano’s wild swing because we’ve already seen him as a man whose ego sometimes makes demands that his brain can’t pay off. He’s enraged by the frontal attack on his inner circle of friends, and his judgment is clouded by some serious sleep deprivation. The possibility that he stands to profit from kickbacks tied to his transit project might also be fueling his desperation.

As for Omar the kidnapper, he seems to have things well in hand until his hostage, Celeste, disappears. We should have fun exploring how and why that happened for the remainder of our screenplay’s second act.

Having gotten us to this point, I’m glad to say I have no idea what happens next. If you do, let me hear about it by Sunday night.

And don’t try to solve everything at once. We still have a long way to go.