Coincidences that get characters into trouble are great. Coincidences that get them out is cheating. It’s the deus ex machina of the fiction world.
Don’t know what I’m talking about? Deus ex machina is, almost literally, the ‘machine of the gods.’ It a device used by opera composers of old when they wrote their characters into a corner and couldn’t figure out how to get them out. They simply decided that the gods had been watching all along and had them drop down to Earth long enough to solve everything. It’s a device that’s phony in operas and it’s phony in fiction.
Today I see deus ex machina used most frequently in paranormal stories that have one or two paranormal characters for most of the book. Then, as the climax approaches, suddenly all kinds of other paranormal characters come out of the woodwork and form an army and vanquish evil. Good wins, of course, but even before the battle begins I’ve lost interest.
So whether it’s in opera, paranormal fiction or any story at all, or whenever you’re tempted to use it yourself because it would make things easier, there’s only one thing to say about deus ex machina. Don’t do it!