The Playful Lady of the Cold-Faced Earl

A girl living in the 21st century suddenly traveled to ancient times, and also traveled across the ocean to Europe. She met a cold-faced count that she loved and hated, and accidentally became a countess! He often has a straight face, sometimes hot and cold, but he seems to care about himself very much, and will risk everything to save himself when he is in danger. What will be her fate in ancient Europe? And how will the relationship between the two develop?