In the Season 4 premiere, we see Joanna take on Oro North, a mining company that wants to open up a mining company in Millwood. Joana's client, Helen Graham is heavily against it because she thinks the land should be protected.
Soon after, Joanna is kicked out of her mommy's group because the other moms think Joanna isn't committed enough and she's putting her daughter in danger by taking this controversial case.
She and Helen almost settle with Oro North until their lawyer, who Joanna once mentored, starts taunting Joanna about her legal tactics and why she really left Toronto.
Joanna and Billy argue about the case. Billy thinks she should let this one go and focus on their daughter. There is a running joke that the baby's name keeps changing.
He's having to defend her in town everywhere he goes, from his dad to Owen, as everyone thinks the mine will add more jobs.
Joanna appeals to the judge for a 30-day adjunction. She compares Oro North to the Music Man and says that she used to be the Music Man's lawyer. She doesn't want those mistakes made again.
Taylor is now Officer Matheson and is working undercover on a drug ring. She and her partner stop one of the vans and find three girls possibly involved in a sex trafficking ring.
Luna and her new girlfriend Stevie help a young woman who was unlawfully evicted, Luna gets an offer to work for Nevin Page, the lawyer who represented Clear Dawn in Season 3.
Helen is hit by a car. Joanna suspects it was on purpose and is more determined than ever.