Confronted with rows among rows of caged animals, many hurt and all of them scared, Jo-Anne McArthur wields her camera. She has snuck in under the cover of darkness seeking evidence and documentation of the horrific conditions animals are subject to; conditions too often ignored. McArthur walks away from the site, but the animals remain captive, and will surely be killed.

“Leaving is the hardest thing,” says McArthur during an interview in Toronto. The 36-year-old photojournalist is the compelling and compassionate centre of The Ghosts in Our Machine, a cinematic and evocative documentary by Liz Marshall. Ghosts played at the Hot Docs Film Festival earlier this year, and it has earned a short run at Bloor Cinema. As the film opens, McArthur and a team of activists prepare to infiltrate a fox farm at an undisclosed location in Europe, and upon arrival, the sights and sounds are simply heartbreaking, and that’s just as a viewer.

For McArthur, though, this is unfortunately familiar territory. She explains soberly in person, just as she does in the film, that she is haunted by her work. For over 10 years she has photographed and catalogued the plights of animals in human-controlled environments, as people continue to use creatures on this planet for food, clothing, fur, and entertainment, caring not for the process, but only the end result.

“I think I will have the greatest effect by documenting issues and making them visible,” explained McArthur, who runs a project called We Animals, an endeavor that looks to change the way in which people view animals on this planet. “I acknowledge the lives of every individual that is kept in these horrific conditions. I just know what my skills are and how I can bring awareness to their particular issue. I’m trying to use my skills to do the best I can and bring the most exposure.”

“There are a lot of reasons to be angry in this world. There are a lot of things to fight against, but that’s using up a lot of energy. I have to be very specific about how I use my energy.”

Exploring the cruel world of factory farms and animal testing, among others, the documentary is indeed about objective presentation. Marshall’s filming matches the tone of McArthur’s photos, which are shown throughout; neither of the women condescend, patronize, or antagonize. They reveal a world that is inhumane, unnerving, and tragic.

McArthur now finds herself in front of the camera for the first time instead of being behind it, something she never hesitated to do. “To say I made a decision is to give it more weight than there actually was,” she says, laughing. Marshall had long followed McArthur’s work, and wanted her to be the central figure in a documentary about animal rights. “I decided long ago that it’s important to talk about these issues and be willing to be super open about what I’ve done and what I’ve needed to do to get into these places.”

McArthur is plagued at times by her work, having been diagnosed with Post Traumatic Stress Disorder just a few years ago. One way in which she balances out the hardships of such emotionally taxing engagements is by often visiting Farm Sanctuary in western New York. The movie follows McArthur on a visit to the animal haven, where the grass seems far greener and animals are treated to wonderfully loving and enjoyable lives. They’re given human names as well, naturally.

Ghosts, thankfully, balances out the more distressing scenes, which take place in factory farms, animal laboratories, and a slaughterhouse, with some time spent at this Eden of a farm. A calf is rescued and cared for, pigs roll around the in the hay, and animals can bask in the sun all day.

Meanwhile, McArthur tirelessly continues to promote the film, and is nearing completion of a book of her work. She is indefatigable, traveling the world, taking pictures, and acting as a lens for those who have no voice. The work is traumatic and haunting to be sure, but a picture is powerful, and Ghosts is staggeringly gripping.

“I have a lot of work to do and I think it’s important, I can’t spend time being depressed, I have to nip it in the bud. I can’t spend time thinking about the fact that I’ve left. I’m trying to the best work I can do and trying to do as much work as possible.”

The Ghosts in Our Machines will plays at Bloor Hot Docs Cinema on July 3 and 4, with McArthur in attendance and panel discussions following the showing.