Abigail's Mirror

Fresh off a ghostly adventure with her friend Derek, she tries to get him involved to investigate what's going on with this mirror. Like it or not, the mirror - and the supernatural mystery behind it - is going to consume both of them.

Although the mirror isn't connected to the mystery they solved a few months earlier, they are able to use some of what they learned. They find themselves in danger and in the midst of another mystery, one that teaches them about time travel, and whether it's possible to alter the past.