The three books are: Although not a direct sequel to The Age of Misrule, it is a continuation of the world established by the end of this trilogy, the events of which are referred to as the Fall.
They do not need to be read in order of publication, although The Hounds of Avalon does bring together the characters from the other two and is set after the events of The Queen of Sinister and The Devil in Green.
Everyday people face the hardships of living in a world with little law and order, poor communications and a Government that is struggling to maintain power.
Mark Chadbourn uses the gods of Celtic mythology referred to as the Tuatha Dé Danann within his books and the idea that Ley lines and ancient sites such as Stone Henge are connections to, and areas of, the Earth's energy which he calls the Blue Fire.
He draws on the theories of Brane cosmology to create a multiverse, where time in one dimension moves at a different rate from another; one hour in our world could be days or weeks in another.
The Devil in Green centres around Mallory, a recently recruited Knights Templar based at Salisbury Cathedral, his comrades and his relationship with a new age traveller/Wicca called Sophie.
During a mission to rescue a vicar, Mallory finds himself in one of the courts of the Otherworld where he learns of his destiny as a Brother of Dragons; one of 5 chosen by Existence to help restore the balance of light vs. dark in our world.
During the siege his friend, Miller, is nearly crucified but saved when Cernunnos places a fabulous beast hatchling within him, infusing him with the Blue Fire.
Mary is visited by an old Professor named Crowther, who says Caitlin is a Sister of Dragons, and that she must find a cure for the plague in the Otherworld.
Caitlin goes with Crowther, meeting up with three others; Mahalia, a teenage girl, Carlton, a mute boy, and lastly, Matt, who is looking for his missing daughter.
Whilst in the court of Lugh in the Otherworld they rescue Jack, a teenager from our world, who was taken as a baby by the Tuatha Dé Danann during The Age of Misrule He has had placed within him a powerful weapon known as a Wish Hex.
Once there she is given a choice to remain as its queen, with her son, in exchange for giving up being a Sister of Dragons, the fight for Existence and a cure for the plague.
The title of the book is the position Caitlin is offered in her deal to save her son This story is set mainly in Oxford where the Government is trying to restore law and order after the Fall.
The title of the book refers to The Hounds of Avalon, who once heard baying indicate the end of the world Brothers and Sisters of Dragons: Other important humans: Celtic gods (the Tuatha Dé Danann) and Courts: General themes of the trilogy are the core issues of our own Dark Ages - faith, plague/illness, war/politics.