The Crystal Children: Keepers of the Blade

After their journey to water bearers, Rune has returned to the US to rescue her own brother and sister from their abusive foster father and take them back to the rest of the group now holed up in Scotland. Alisdair must take the reins and keep his part of the crew safe long enough for Rune to return and help them fight off the mythical beasts of the Scottish underworld while looking for a legendary weapon that will not only join Bean and Fane together as the new water bearers, but also resurrect the deceased keepers of the spirit crystals, all while trying to evade the evil that threatens to wake a being so ancient that once awoken, the safety of the entire planet will hang in the balance