The Cross of Constantine — Odette C. Bell

An action adventure packed with danger, mystery, and just enough romance, the Trouble and Treasure series follows the adventures of Amanda and Sebastian as they try to track down one of the most valuable treasure maps in the world.
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Book Two of the Trouble and Treasure Series:

Two months after their first crazy adventure, Amanda and Sebastian are back together again. And once again they're in trouble. This time Amanda has come to the attention of a rather fabulously rich and unscrupulous antiques dealer, and Sebastian is forced to pull every trick he knows to try to keep her safe. Before they know it they are in Paris, and before Sebastian quite realizes what he's doing, he's kissing Amanda up against a wall.

Can Sebastian and Amanda safely navigate their way out of trouble while still finding the treasure?