Rachael died in the Vatican led purges for witchcraft six centuries ago. Deemed too good for Hell and too stained for Heaven, she was destined to be a lost soul until she learnt to summon her own form and became the first dark angel. Living a tentative existence in London, Rachael draws energy from pleasure to maintain her form but her soul is being sought by a demon. If the demon Mastema can burn her soul, he can use the energy to open a portal to Hell and London will become a new realm of Lucifer's domain and from there, world conquest is a small step. Ranged against the demon-spawn are the angels of the Host; led by Briathos, the angels seek to draw Rachael to the light but they know, should they fail, they must see her destroyed. Rachael has resisted choosing sides in a war she has no part in but in the interest of survival, she has to consider compromising her lifestyle and facing dangers in order to prevail. Through the trilogy, the stakes raise as greater demons are drawn into play and when Archangel Michael has to become involved, the true risks are finally revealed. At the close, mankind must stand with the Host against the Fallen Angel himself.