Coal Valley’s newest addition, young schoolteacher Elizabeth Thatcher, is getting adjusted to her new life on the frontier and her new home with kind Abigail Stanton, just as handsome and mysterious Mountie Jack Thornton, becomes Coal Valley’s new Constable. The undeniable attraction between these newcomers is apparent, but as Jack gets to know Elizabeth better, he questions whether her high-profile family background is the reason he was assigned to Coal Valley, sparking a feeling of resentment between the two. But they are both distracted by the recent tragedy—a coal mining accident that killed many of the small town’s men, and left grieving widows and children behind.
As Elizabeth nervously teaches her first class, feeling pressure to do a good job with the children, the town suddenly goes up in arms when a plank with a personal message is found in the rubble of the mine disaster, and many of the widows claim the plank was written by their deceased loved one. Jack makes his first decision as the town authority, stating that coalmine head Henry Gowen will find the correct owner of the plank by comparing writing samples provided by widows. But when the plank mysteriously disappears, Jack and Elizabeth must work together to get the special message into the right hands, finally warming up to Coal Valley—and to each other.