The Kin

Book 1 of the Custodians: Rome, present day: David Lowe arrives to research myths and folk tales. Studying in a library that seems to have as unusual a personality as it's Custodians.
Parthia, second century A.D; Two legionnaires, far ahead of Emperor Trajan's legions explore the dead city of Persepolis and unwittingly unleash a force more deadly than any the Roman empire has had to face before.
Separated by nearly two thousand years, they all struggle to deal with a world that is far less illuminated than they thought. The lesson remains the same.
Be careful when you push in to the Dark. Sometimes it pushes back.