There are times, though, that we use in our stories events that might make readers skeptical. Here are some ways I've found to make the implausible more plausible in fiction.
- If your premise is too weird or far out to be believed, postpone it. Open the book with related tension --- but not the full low-down --- that keeps building while at the same time deeply investing us in the character(s). Work in any necessary knowledge or background (history or science, for example) that will be needed for the reader to buy the premise, as the tension- and character-building continue. When the far-out premise is finally revealed, readers will hopefully be so emotionally in tune with the characters (their fear will be the readers' fear, for example), and so prepared by the groundwork, that they will accept the big reveal. Examples: Unwind by Neal Shusterman; The Aviary by Kathleen O'Dell.
- An aspect of the above: Make a believer out of your MC. Then make readers believe in your MC. Or vice-versa. This will help readers believe what the MC believes.
- At the same time, try making one character a disbeliever. Let that character voice all the objections to the implausible aspect that you'd expect readers to voice. Readers feel a lot better when they know you know something's fishy, and will often cut you some slack if a character is saying the things they wish they could say. Then let other characters either prove the disbeliever wrong, admit he might be right, or take his objections into account when planning the next action. I think it was children's author Sid Fleischman who said, "If you can't cut the implausible element, point to it."
- To make a villain believably scary, make sure he holds a valid point. If he's right in some way, that's scary. Also identify something good about him. Does he love his mom? Make him human. Is he a gifted musician? Make him normal. Does he love ice cream and forget to empty his pockets before he washes his jeans? Reveal some background that creates sympathy for him. The abusive man in Kathi Appelt's The Underneath broke my heart because of how he'd been treated as a little boy.
- If you're using an unlikely event in your story, list as many reason as you can why such a thing could not happen. Then look at each obstacle in turn, and work out at least one reason why this obstacle will not prevent the event.