After briefly eluding Yassir Ali's ruthless assassins in England, Nick, Marie, and Ishi have fled north, where they hope to track down a forgotten cavern in the Highlands of Scotland.

The cavern is linked to the Ambrosius Amulet, and is said to contain the greatest treasure of gold, jewels, and other artifacts ever amassed by the ancient druids. But, finding this sacred place won't be easy-especially when those trying to kill the forlorn trio are hot on the trail again.

It doesn't help matters that Nick and his cohorts' search is limited to details from a conversation Marie had with her father prior to his murder a year earlier. His last wish was for her to complete the task he couldn't, and was the main reason Marie hired Nick as her archeologist guide in the first place. Now, after being chased relentlessly through Europe by Yassir Ali's hit men, they finally possess the key to finding the druid treasure. Yet, the Ambrosius Amulet can only tell them when they have found the right location.

The task of locating the correct 'marked' Scottish hillside must be handled on their own, using natural means. Relying on Marie's memory of landmarks and coordinates given by her father, the task of searching Loch Ness, Loch Lomond, and Loch Morar quickly becomes a hazardous affair.

Will one of these famed locations prove to be home to this fabled treasure of the early Brits? Or, will this be one myth that can't be solved, either by fate or bullets from a ruthless enemy closing in? These questions, and more, are waiting to be answered in the Secret of the Loch.