Plymouth Sound.
Book One in the Plymouth Grey series.

Plymouth.
A city under siege.
Only no-one knows it.

Alex has come to see his grandfather but instead finds himself caught in an unearthly battle with an eerie smog-bound Plymouth as Ground-Zero.
From the modern-day city to secrets from the Elizabethan era Alex discovers a Plymouth he never dreamed existed.
To have any hope of surviving against the monsters hiding in the smog he must put his faith in a group of strangers who seem to know far more about his grandfather than he does.

The Plymouth Grey.
The first line of defence against paranormal threats affecting Plymouth.

A group whose only link between the members is the mysterious Incan crystal pendants in the treasure Sir Francis Drake took when he attacked the Spanish treasure ships in the South Pacific Ocean.
Their unique properties were only realised when he arrived back in Plymouth.
Even today their uses are still largely unknown.