Fierce Highland Guardian (audio book)

Reckless Hearts of the Highlands Series, book 1, A Scottish Romantasy Novella

She came to Scotland to study the past. She never imagined she'd uncover a legend that breathes fire.
Dr. Fiona Vale has spent years choosing safety over passion. After a quiet divorce and a lifetime of playing it safe, the American archaeologist arrives at the storm-battered ruins of Dunnottar Castle wanting only solitude, her research, and a chance to disappear into the work. What she finds instead, on a night of crashing waves and lightning, is impossible: a massive black dragon rising from the sea—and shifting into the form of a man.
His name is Caelan. He is the last guardian of an ancient hoard buried beneath the cliffs, and the keeper of a relic powerful enough to wake Scotland's oldest and most dangerous magic. For centuries he has trusted no one, because the last time dragons trusted humans, betrayal nearly destroyed them all.
Now ruthless treasure hunters have come for the Heartfire Stone, posing as scholars and hunting for the very secrets Fiona was sent to find. As ancient enemies close in around them, Caelan must decide whether to reveal the truth he's guarded for a thousand years—and Fiona must choose between the careful life she rebuilt from the wreckage of her old one, and a love that could cost her everything.
Because some treasures can't be protected by walls or fire.
And some can only be saved by trust freely given.
Windswept cliffs. A brooding immortal guardian. A heroine learning that the greatest risk of all is letting someone in. Fierce Highland Guardian is a standalone gothic romantasy—the first in the Reckless Hearts of the Highlands series—for readers who love slow-burn tension, dragon shifters, and the kind of love worth burning the world down for.
"You don't win love by playing it safe."