Schools starts with an awkward encounter for Elizabeth as Lucas tries to share his notes on her latest chapters, only to be interrupted by the arrival of students and Nathan. Elizabeth gets past the encounter, but a new challenge arises when Opal’s arms begin to itch. Elizabeth rolls up her sleeve and finds pox marks. Allie remarks, “That ain’t good.” Shortly after, Dr. Carson confirms Opal has chicken pox. It’s highly contagious so Elizabeth dismisses class immediately.
Bill hears Sean Murphy’s lawsuit against Henry. He claims Henry sold him sour oil. Lucas is a silent partner but pipes up and asks Bill for a jury.
News of chicken pox continues to spread through the town as Elizabeth warns Rosemary. Rosemary, feeling itchy herself, immediately seeks out Carson. Rosemary felt she was one of the lucky ones as she has never had it as a child, but Carson confirms she has chicken pox which can be dangerous for adults. He advises her to go home and rest immediately.
Bill works on finding potential jurors for Henry’s trial. It proves harder than he assumed with only Clara, Florence and Ned as prospects. Henry also seeks help in his case, asking Nathan to do some digging at Murphy’s refinery to find a way to sort the oil mess out.
Elizabeth also enlists Nathan’s help to warn the elderly and those outside of town that chicken pox is spreading. Lucas overhears this and inserts himself between Nathan and Elizabeth by offering to help spread the word.
As Nathan and Lucas set out from the courthouse to spread the news of chicken pox, Nathan chastises Lucas for being late. Lucas counters that he is not the only one that cares about the town. Nathan gets candid, saying the town - really Elizabeth - is not here right now so if he wants to bow out, he can. Lucas keeps his word to help. Nathan knows they both have mutual feelings for the “town,” but still appreciates the help.
Rosemary begins to go stir crazy in bed, insisting she is fine and has a thousand other things to be doing. Lee refuses to let her out of bed or leave her side. He wants to be available if Rosemary needs anything. Rosemary would love a cup of Chamomile tea, but they are all out. Lee is happy to grab some more from the store and heads out immediately. Rosemary sees this as a chance to get out of bed. However, the joke’s on Rosemary as when she heads downstairs and grabs her sketch book, Lee catches her red handed. He commands her back to bed and notices her energy dwindling.
Despite Lucas’s suggestion to push the trial and avoid the trouble, Bill starts jury selection. Meanwhile, Nathan checks out Murphy’s Refinery and learns from the foreman Cornell Frolich that Henry’s crude oil is low grade and there are test results to prove it. Nathan takes the information at face value, until he relays this message to Henry. Only then does he learn that Frolich used to have an oil company of his own that competed with Henry’s, but it recently went bankrupt. Nathan returns to Frolich’s office, warning that falsifying reports is a criminal offense. If he and his son give false testimony at Henry’s trial out of revenge, one of them is going to jail.
Faith is on the way to her stagecoach to Chicago, where she will begin her medical course to become a doctor. However, when she learns Rosemary has a fever she rushes to her side. Lee tracks Carson down at the stagecoach to let him know Faith is with Rosemary, who has developed a fever. Carson joins Faith to get Rosemary’s fever down. Carson needs to do submersion therapy to break her fever.
Nathan tells Bill, Henry and Lucas that Frolich’s son tampered with the oil quality test results. He blamed Henry for the demise of their company and was looking for payback. Bill closes the case. There are no hard feelings between Sean Murphy and Henry, but Lucas wonders why Frolich and his son accused Henry of putting them out of business. Henry’s reply is that fewer competitors means bigger profits and business is a blood sport. Lucas is taken aback by the response and admits he heard Henry was a ruthless businessman. Bill sums it up saying, “Just when you think he’s turned over a new leaf, he cuts down the whole tree.”
When Rosemary’s fever breaks, she apologizes to Lee for giving him a fright. Later, Elizabeth visits and Rosemary insists she catch her up on everything that happened while she was ill. Elizabeth says there will be plenty of time for that later and tells her to rest. Rosemary agrees and says between her loving husband and wonderful friends she is one of the lucky ones.
Meanwhile, Carson tells Faith he could not have made it through the night treating Rosemary without her. He insists Faith still has enough time to head to Chicago to begin her class. Later Carson checks on Rosemary, whose temperature has fallen and appetite returned. Lee thanks Carson for his help. Rosemary also thanks Lee for taking such good care of her.
Clara wonders why Bill is not more relieved the trial is over. Bill is just disappointed the jury was put together for nothing. Jesse reminds him with Henry in town he’ll have plenty more opportunities. At the same time Lucas warns Henry that his business practices were borderline unethical and wonders where he’ll draw the line. Henry’s response is he’ll let him knows when they get there.
Nathan finds Elizabeth’s loyalty to her friends admirable as they head to wish Faith good luck. Faith is touched by the town’s send-off, which includes supplies to write home, hugs and sandwiches. Carson says the time will go by quickly, although Florence asks if he is telling them or trying to convince himself. Faith tells Carson she misses him already. They each say, “I love you,” share a kiss and wave goodbye. As Faith rides off in her stagecoach, she looks at a photo of herself with Carson and smiles.