When Characters Behave Out of Character

I think most readers agree that one thing that immediately forces them out of a story is when a character does something out of character. Occasionally authors need a plot device to forward the resolution of the story and some poor character will have to do something totally contrived.

"Why," wonders the reader, "would Kathy go into the clearing alone when she knows there's a ravenous T-Rex there? She's always been perfectly rational before…did she have a small stroke?"

Sometimes I can...