Talk about a nail-biter of a midseason finale. Sunday’s newest episode of Heartland, the final one of 2015, was unlike any I’ve seen since I started watching the show. Gone were the feel-good, happy endings we’re used to getting, replaced by scary scenes and poisoned animals.

The focus of “A Matter of Trust” was Georgie and Lou’s deteriorating relationship. Heartland hasn’t shied away from portraying the struggles associated with a family ravaged by divorce, but Sunday took another step, first by having mother and daughter wage war over lies, trust and responsibility and then with Georgie running away to Vancouver and leaving her cell phone behind at the ranch. Yes, Georgie is maturing and moving past that awkward phase and taking her first tentative steps into being a woman. She’s not there yet, but she sure wants to hang with and be accepted by the older girls. Everyone can relate to a storyline like that, and Georgie’s feelings. This being Heartland, I’m assuming Georgie will make it to Peter’s door unscathed, but that knowledge certainly didn’t take the edge off that final scene of her alone in the dark and wandering down the street. (As an aside, I hope Michelle Morgan receives a Canadian Screen Award nomination for her work this season; she deserves it.)

Meanwhile, an environmental disaster threatens the life of Phoenix. It’s been awhile since Heartland dealt with that angle, and having Rusty and then Phoenix succumb to poisoned water was tough to watch. Rusty has been treated and is on the road to recovery, but Phoenix may not be so lucky. Georgie’s disappearance means he’s not getting any attention and he needs someone to notice he’s not doing well. Fingers crossed Amy or Ty head back to the barn and discover the horse is in bad shape.

Heartland returns Sunday, January 10, at 7 p.m. on CBC.