When a wooden plank inscribed with a sentimental message is discovered in the mine, new constable Jack Thornton tries to discover the plank's rightful owner. Elizabeth struggles with capturing the enthusiasm of her students in the wake of tragedy.
When all the widows in Coal Valley receive eviction notices from the Coal Company to make way for new miner recruits, Elizabeth hatches a plan to keep the widows from moving out of the only town they know.
Elizabeth helps a mute student who is struggling to cope with the death of her father. Jack investigates the mysterious circumstances surrounding the burning of Coal Valley's only church.
After finding the cans of whale oil, Jack investigates Cat Montgomery for her possible involvement in the church arson case. When the evidence points to Cat, Gabe becomes infuriated by the idea of his mother being imprisoned for something she didn't do.
When a group of new male miners comes to Coal Valley, many of the town's women get caught up in the idea of the single men. One of the new miners begins courting Elizabeth and Jack seems to have concerns that resemble jealousy. Abigail takes in Carla Noonan, a pregnant widow, to keep an eye on her health while Coal Valley's doctor is away.
The Miners' Games allow the townspeople to cut loose and have a little fun. Elizabeth is feeling caught between overprotective Jack and new miner Billy Hamilton, but when Jack tells her he has proof Billy lied to her, Elizabeth decides she's had enough. Abigail suggests Jack try a gentler approach to reach Elizabeth. Jack also investigates a series of robberies that are plaguing Coal Valley.
Abigail is encouraged to reopen Coal Valley's dilapidated and abandoned cafe and make it her own after Elizabeth raves about Abigail's baking. Jack accidentally insults Elizabeth as he fumbles to confess his feelings for her. One of Elizabeth's students has trouble reading so she enlists Jack's help for a creative solution.
Elizabeth and Abigail move into rooms above Abigail's cafe. The only surviving miner from the explosion comes home from the hospital with a shocking surprise. Elizabeth and her students must put on the Coal Valley Founders' Day play on short notice.
Jack makes his intentions known by asking an excited Elizabeth on date. Her younger sister Julie (Charlotte Hegele) also makes a surprise visit. Julie wants to know all about Elizabeth's new life and her new romance. Elizabeth is careful with her emotions, until she sees the romantic evening at the café that he and Abigail planned for them. However, Jack has been granted a transfer to another post, which he requested upon arriving at Coal Valley. Now happy, he must break the news to Elizabeth. M
After Jack's departure from Coal Valley, Abigail learns her husband might be at fault for the mine disaster. Julie unknowingly nurses wanted outlaw Nate Tolliver back to health and gives him directions to the cabin where they met, and where his loot is stashed. Julie confides in Elizabeth about her newfound love, but a suspicious Elizabeth goes to tell Abigail, just as the trouble arrives. The Thatcher women are put in danger, and Elizabeth realizes that love is stronger than fear.
After taking care of the Tollivers, hero Jack returns to Coal Valley. His ex-fiancée Rosemary LeVeaux also arrives. Rosemary broke up with him long ago to become an actress. However, she now seeks to make Coal Valley her home and Jack her husband, putting Elizabeth at odds with Jack. Meanwhile, he has asked forensic investigator and friend Bill Avery to help Abigail in regards to Gowen, the mining company and the explosion. As Bill works with Abigail, he becomes interested in her, admitting his
Coal Valley is finally going to get some justice for the mine explosion when Circuit Judge Jedidiah Black comes to town. Jack confronts Elizabeth about her teaching offer. Abigail begins letting go of the past and starts looking to the future with Bill Avery. Jack and Elizabeth's relationship changes in a big way.