This small-town drama has quietly become a hit on Netflix. Fans credit its relatable charm and unmatched cliffhangers.

A city girl relocates to a sleepy town to restart her life, reconnect with her family and turn over a new page. It’s not Cousins Beach, Mass.; Ransom Canyon, Texas; or Serenity, S.C. And it’s not Virgin River, Calif., either. But it’s close. Welcome to Timberlake, the picturesque Canadian town at the center of Sullivan’s Crossing — a leafy, idyllic...