This happens to me a lot when I'm writing: I need an event to happen, or some characters to interact, but I can't figure out a way to make it happen naturally. I'll run through several scenarios, but toss them aside because each one feels forced or implausible. "That would never happen," I say, as my writing grinds to a halt. Meanwhile, my little slice of daily writing time is dwindling and I'm no further with my story. The solution?

Quit discarding ideas! I have to force myself to latch on to the least bothersome option and just write it or else my story will go nowhere. I might have to grit my teeth or hogtie my inner editor to get it done, but once the necessary scene is written, the "good" parts of the story can flow again. It's like a broken down car on the highway. One little car with its hazard lights flashing can add up to a 2-hour traffic nightmare for anyone stuck behind it, but if a couple people push the car off to the side of the road, all travel lanes are suddenly back in business.

Sure, you need to get back to your broken down car of a scene - someday - but not right away, and maybe not even while you crank out your first draft. It'll still be waiting for you when you have the time and energy to face it, and why block up the rest of your story in the meantime?

A chance encounter between two characters might feel contrived and gimmicky to you, but if it's written well and serves the story, it will likely work for the reader. A character taking a right turn when he should have gone left and ending up exactly where you need him to be is perfectly ok for an author. Don't obsess on why he would make that turn, or why he got to the parking lot in the nick of time. Just write the scene and keep your story moving. You can always rewrite it later, and quite often, it's not as bad as you originally thought. (Readers can be a lot more forgiving than authors in this regard.)

Similarly, you can give yourself the latitude to throw in completely impossible elements if they mean you can move beyond a block and keep your story going. Phone call from God to get your main character back on track? Sure, why not? A high-powered rifle in musket times? Go for it. My worst example of this took place when I needed a group of characters to break into a university office and steal a book. As it was originally written, the characters caught lucky break after lucky break and were able to pretty much waltz in and take what they needed. It was horrible on the first pass, but it let me bring that book into play, which led to much more interesting and complex scenes. When I went back to that scene a few months later, it wasn't as bad as I remembered it being, and it only needed a few additional obstacles for the characters before it flowed perfectly with the rest of the story.

No matter how implausible it may seem, don't let yourself get hung up on details on your first draft.