Do you have any tips for introducing a ~mysterious~ character without an info dump? My main character appears in the second chapter, and is on the run from the law - but I don't want to reveal this straight away as this side of her story is unpicked later on. How can I introduce her without it being boring or seeming random?
Introducing any character without an info dump should be pretty easy- don’t write one- but writing one for a mysterious character immediately kills the mystery. For a mysterious character it’s best to have as little description as possible.
You should make her introduction seem commonplace. When running from the law it’s probably best not to enter a room dramatically and shout “I HAVE A MYSTERIOUS BACK STORY, NOTICE ME.” No, she will either distance herself from everyone or fit in so well people can’t imagine her not fitting in, i.e. by being a fugitive. However, since you want the reader to find her quickly interesting (which is not a requirement, btw, slowburn characters can be captivating too) there are ways to make her introduction noteworthy.
In the first sentence that introduces her make her do or think something that wakes the reader up but draws little/no attention from fellow characters. Maybe she sees a homeless man sleeping in a bus stop and immediately assumes he’s dead. This is both jarring and confusing since one can’t automatically assume any sleeping person is dead, even a homeless one, but perhaps later on we find out that her previous experiences have her expecting death at every turn. Perhaps we find her contemplating shoplifting, pawning something valuable, or hiding behind a decorative urn because she thought she saw a cop car. Random introductions like these, as long as they are out of place with the rest of your story so far, will notify the reader that this character has some unspoken issues.
Most importantly, do not explain any of her behavior. If enough things around your character are written without explanation, everything around her will become suspect to the reader. Once the mystery is fully revealed readers should understand her previous strange behavior without you having to tell them. Until then, less is more.