Writing.Com General Discussion

There are two things I'd be thinking about in this situation.

The first is to ask myself whether the 4th character is just a device to help bring about the conclusion I want. If that's true, then I would rethink that character. Think of it this way: you have a story where the protagonist is clearly not competent to defeat the antagonist, but right at the last minute they trip up and spy a handy weapon under the sofa and can therefore win the day.

This is artifice in such glaring terms the reader is going to question its validity.

The second is to ask myself whether I can sneak the character in earlier. There is absolutely no problem in having a thread which seems to bear absolutely no relationship to the rest of the story - a scene here and there sprinkled through the story that tells the 4th character's tale. The reader will be left wondering why of course, but when that thread collides with the main protagonist's (at the point you have already slated for the character's introduction), it will all suddenly make sense.

Many stories are written this way - two (or more) disparate threads that seem unrelated, yet will eventually come together and the reader will discover the relationship between the threads and the reason they were reading them in the first place.

If you leave it too long to introduce the character, you are in danger of turning them into a device to keep the story on-track. If the reader sees them this way, then the author's hand is exposed and all immersion is lost. On the other hand, you may have enough time to explore that character in the remainder of the story such that the immersion isn't lost. Since only you know the story, this will have to be a judgement call on your part.

The good news is you can try both ways. Try it with the late introduction and then when you've finished your first draft, read the story and see how you feel about it. If you think you need to introduce the character to the reader earlier, it would be simple enough to sprinkle a few additional scenes throughout your story.