At its core, The Lazarus Effect is a Frankenstein story. A group of doctors attempt to eliminate the divide between life and death by experimenting on euthanized animals with a new medical serum. The succeed with a dog, only to discover the serum does much more than revitalize the body.
There's enough going on in this initial layer of concept to sustain an 80 minute horror film. The problems in The Lazarus Effect come from attempting to include a whole lot more. The result is not a coherent narrative, but a collection of isolated and successful scares.
One doctor, Zoe, has incredible guilt lingering into adulthood from her Catholic upbringing. It manifests in a recurring nightmare about a fire in her childhood apartment building that trapped her neighbors. She also attempts to reconcile belief in the afterlife with science, creating some interesting tension for a central figure in a film.
There's also a documentary student, Eva, brought in to film everything that happens. That means some found footage/shakycam nonsense during some of the big scares during experiments. It's totally hit or miss and the character really exists as a deus ex machina for the final act. She's the ultimate outsider in the experiment, with no working knowledge of how any of the theories (religious or scientific) work at all.
There's more. An evil biochemical corporation buys out the company sponsoring the research and shuts down everything. A dog brought back from the dead turns ghostly and evil. Everyone is trying to get with Dr. Zoe (a total waste of a character introduced as the brains behind the entire experiment). A lot of the scares are lifted from body horror cliches and anxieties. The rest are paranormal slasher territory. And there's the ambiguous, existential threat of discredit in academia among other concepts.
Medical ethics have a long history of playing a big role in horror. You don't need much more than that to get a Frankenstein-derived story in motion. Adding in sexual tension, religion, possession, psychic abilities, body horror, slashers, societal pressure, even found footage can be a great way to focus in on a different angle. However, when you throw every connected archetype, cliche, and theme into one story, you're guaranteed to miss the mark on all of them.
The Lazarus Effect is scary. The performances and effects are good. The technical qualities are strong. Each scene, isolated from the rest, is good horror. Taken all together, you get an ambitious horror film that fails because it refuses to commit to a central concept. It's an interesting failure, which is always a lot more interesting than a predictable retread of an idea learned by rote.
The Lazarus Effect is currently streaming on Netflix.