Kian Ap Rhys– With green fire, fire of the earth, he left his world to find the thing that had stolen his Uncle's Fire.
Regan Campbell– A human. A hunter of the Nameless. He has the infant red Fire of a healer.
Darach Gravenor– Blue Fire, the water fire. He is left alone when Kian goes to another world and he needs Cariad Fire and Magik to cross after his friend to rescue him.
Ceithin Morgan– Of the Cariad tribe, his Fire is the red of a healer.
Eoin Gryfyth– Holder of Amber Fire; the greatest and most prized of all Fires. He is Guardian to the City and rules the Council of Three.
Trystyn Morgan– Cariad and Brother to Ceithin with amber Fire. He was kidnapped as a child and is missing
Wynn– the Guardian before Eoin
Fire– the magic that resides inside all of us. In our world we have Fire inside of us all but we only see it as inspiration or talent. In Kian's world Fire defines each person's magik. There are four colors of Fire. Red for a healer, green for the earth, blue for water, and amber.
Cariad – a tribe of people who live by the old ways in Valleys outside of the main City. Ceithin and Trystyn are Cariad.
City – the place where Kian, Darach and Eoin lived
Blood Bond– a bond sworn by Kian, Darach and Eoin as children in fun.
The Nameless– Humans from our world who have had their 'essence' of life sucked out of them.
Eicio– What everyone apart from Regan called the Nameless
Annwn– A curse word, literally meaning 'Hell'
Guardian– Each generation has a holder of Amber Fire that is stronger than all. They become the Guardian to the City and lead the Council of Three.
Council of Three– Ephraim, Sulien and Madoc, holders of amber Fire.