The Alexander Inheritance is another spin-off of the Assiti Shards/1632 series.
The Ring of Fire incidence hits Earth for the third time as an ocean cruiser disappears off the Pacific Ocean. Reappearing in the Mediterranean, the ship heads to Egypt at the behest of a historian.
They make it, only to find out they are stuck in the past.
It's been two years since Alexander the Great has died and his great empire divided among his generals. The political instability would lead to the Diadochi wars, several civil wars which would destroy the Ancient world.