A series of murders take place in various cities, and the suspects claim that they were killing demons. The Justice League can't ignore these events, and Batman (voiced by Jason O'Mara), a detective at heart, decides to get to the bottom of them. He approaches Zatanna (voiced by Camilla Luddington), a famous magician who is actually, unbeknownst to her adoring fans, a powerful sorceress, and asks for her assistance. Deadman (voiced by Nicholas Turturro), a spirit who can possess the living, also shows up in Zatanna's dressing room, and the three go in search of Constantine (voiced by Matt Ryan), a con-artist who straddles the world between the living and the dead. Constantine, who lives in a inter-dimensional dwelling call The House of Mystery, reluctantly agrees to help them. Constantine recruits The Demon (voiced by Ray Chase) to help as well. Thus begins a international trip to various supernatural entities to try and find the truth before more murders occur.

What is surprising here is the execution. Most DC animated titles are based on a specific comic book or story arc. While there is a Justice League Dark comic title, it appears that this film is an original story taken from the comic's concept. The result is obvious, as the movie has a real lack of focus. This project can't decide if it wants to be an origin story or not. We get background segments on The Demon, Deadman, and a brief one for Swamp Thing. However, Constantine, Zatanna, and The House of Mystery are trotted out like we're supposed to know exactly who they are. Just because Constantine has had a movie (which was released 11 years ago) and a canceled television show, that doesn't mean that people know who he is. As for Zatanna, the fact that you've ogled at a scantily-clad woman at a Con has no bearing on your knowledge of the character. The under or over characterization aside, the overall story is also lacking. The plot is meant to be a mystery, but once the villain is revealed, it’s decidedly underwhelming.

Introducing a new team or a group of characters is never easy, but given the reputation and longevity of the DC animated features, one would expect more from this. I can appreciate that Batman goes along for the ride to keep someone familiar on the screen for most of the piece, but he also feels incredibly unnecessary at times. If you are approaching this hoping for a Swamp Thing feature, temper that enthusiasm, as he’s only in it for a matter of moments. The chemistry between Constantine and Zatanna works, but that’s only a part of the equation. As someone who loves horror movies, I like the ideas of characters like this getting their own project. (I would love to see Marvel do something with the Midnight Sons.) But, they deserve a better film than this.

Justice League Dark could have used a lot more Swamp Thing on Blu-ray Disc courtesy of Warner Home Video. The film has been letterboxed at 1.78:1 and the Disc contains an AVC 1080p HD transfer which runs at an average of 16 Mbps. The image is sharp and clear, showing no grain and no defects from the source materials. The colors look very good and the image is never overly dark or bright. The picture shows a nice amount of detail, which sounds like a good thing, but it reveals that not all of the animation here is very sophisticated. The depth is pretty good, as the image never looks flat. The Disc carries a DTS-HD Master Audio 5.1 track which runs at 48 kHz and an average of 2.5 Mbps. The track provides clear dialogue and sound effects. The first thing that you'll notice about this track is that there is a great deal of subwoofer action. Even when the volume is reduced, the bass is still there. The stereo and surround effects highlight the events in the action sequences.

The Justice League Dark Blu-ray Disc features a very random array of extras. "The Story of Swamp Thing" (18 minutes) is a mini-documentary which provides a detailed look at the history of the character. Creator Len Wein and some other DC folks appear here to discuss how the character has changed over the years. Unfortunately, Bernie Wrightson, the artist who created the look of Swamp Thing is absent here. "Did You Know?" (3 minutes) offers four brief segments, "Constantine Origin", "Color of Magic", "Black Orchid", and "Deadman Casting", which give some extra info on the film. "Justice League Dark at New York Comic Con 2016" (27 minutes) takes us to a panel discussion at the Con where the film is discussed. We get two episodes of Batman: The Brave and the Bold, "Dawn of the Dead Man!" and "Trials of the Demon!" The other extras are previews for upcoming DC titles.