From the back page:
Sixth World scholars have long hypothesized the cyclical nature of magic. For years corporations, collectors and other factions have spent fortunes hunting down surviving relics of this mythical age. The shadows whisper of lost lore and a secret history to the world. A privileged few have come into possession of ancient items of great power and mysterious purpose, artifacts from before recorded history. Now it’s your turn...
Eighteen months ago, the Phaistos Disk was stolen from the Herakleion Museum in Athens. Now, Mr. Johnson needs you to find it and bring it back. The hunt will take the runners through the shadows of Europe, and lead to interactions with smugglers, art dealers, and archaeologists. If they survive Interpol, Aztechnology, and an eccentrically violent shadowrunner team, they may just learn who is behind the hunt and why.
Darkest Hour is the third chapter of the Dawn of the Artifacts storyline. This continuing storyline explores the secret history of Shadowrun, and offers clues to the true mastermind behind the hunt for the artifacts