Synchronic's Plot And Ending Fully Explained

Contains major spoilers for Synchronic

Filmmaking duo Aaron Moorhead and Justin Benson have made a career out of surreal, critically acclaimed horror films after bursting onto the scene with 2012's Resolution. This year, the two are back at it again with the surrealist science-fiction-horror film Synchronic, which made a major splash when it first debuted at the 2019 Toronto International Film Festival. 

The film stars Anthony Mackie (the Falcon in the Marvel Cinematic Universe) and Jamie Dornan (Fifty Shades of Grey) as two paramedics who witness a string of horrific murders around New Orleans. Over time, they discover the existence of a new designer drug with which all of the murder victims are associated. Steve Denube (Mackie) discovers a terrifying secret behind the drug and needs to learn all of its secrets in order to save the life of his friend Dennis Dannelly's (Dornan) daughter. 

For the first half of Synchronic, you may be left scratching your head, wondering where all this is leading to. But around the halfway point, everything comes into focus, and you're left on the edge of your seat trying to figure out how the pieces will come together. But you may also wonder what exactly is going on, especially once a particular plot point is revealed. Here's a full explanation of everything that goes on in Synchronic – from its in-universe rules all the way to its ending. 

In Synchronic, the titular drug tears apart numerous lives. As Steve and Dennis go about their routes as paramedics, they come across one grisly death after the next. One person has been stabbed by a sword, while another has been completely burned alive. At first, it just seems like people are getting themselves into situations they should have never been in ... until it's unveiled what Synchronic actually does. 

Steve goes to a marijuana dispensary where Synchronic is readily available and buys out the remaining supply. Someone else who is there wants to take the drugs, but Steve just shrugs him off. Later, the man breaks into Steve's home and reveals himself to be Dr. Kermani (Ramiz Monsef), the chemist behind Synchronic. It's more than just a fancy kind of marijuana: It's a designer drug meant to be a substitute for DMT (a powerful psychadelic) but made with different compounds to skirt around regulations to be legal. 

Dr. Kermani's company rushed the product to market without fully understanding its effects. And, as it turns out, Synchronic transports you to another time period. You get sent to the past, but appear in the same location where you initially took the drug, just in a different year. All those people who died earlier in the film? They were killed in the time periods they were sent back to and returned to the present as corpses. That man was stabbed by a pirate. That woman was trapped in a room in an old amusement park as it burned to the ground. The past is a very violent place.

On one call to respond to an accident, Steve and Dennis encounter a group of young adults, and among the group is Brianna Dannelly (Ally Ioannides), Dennis' daughter. The only problem is that Brianna is no longer there. Steve's told that Brianna was sitting in a chair one minute, gone the next, and never returned. 

Brianna's disappearance comes into a clearer light when Steve has a conversation with Dr. Kermani, during which Kermani discusses how Synchronic works and why it sends people into the past. Synchronic impacts the pineal gland within a person's brain. This allows them to experience time as an all-encompassing presence rather than just in a linear manner as we go through it normally. 

When an adult takes Synchronic, they appear like a ghost in the past. But since kids' pineal glands haven't fully calcified yet, they physically go back to the past entirely, and there have been reports of some teens being trapped there. Brianna is still just a teenager, so when she took the drug, she physically went to another time period and didn't come back. Steve learns this and takes it upon himself to find a way to bring her back. 

Steve gets some upsetting news from his doctor when he's shown a scan of his brain and told he has a tumor on his pineal gland. However, the doctor explains that it's a rather unique tumor: Whereas most tumors on that gland form on the inside, Steve's is located on the top. The doctor goes on to explain that most adults have at least a somewhat calcified pineal gland. The doctor even states that "yours is like a teenager's."

It's an aggressive tumor, and it's one for which they'll need to begin treatment immediately. The doctor says Steve could have six weeks or 60 years, but the tumor is inoperable. This makes Steve the perfect person to try to go back to the past to try to rescue Brianna. Most adults only go back to the past as ghosts or visions, but he can actually go back as a physical presence. It's a critical scene early on in the film that sets up why Steve is the only person who can save Brianna.

When Steve takes Synchronic for the first time, he's transported back to a time when New Orleans was still just a swamp. In a span of just seven minutes, he's attacked by both an alligator and a sword-wielding conquistador. After that, Steve decides to record himself so that he can show a future audience precisely what the drug is capable of. It also makes for a handy plot device so that Steve can explain to the audience what the drug does. 

Through these experiments, we learn some handy details of what Synchronic can do. For starters, the location in which you take the drug impacts which time period you're sent back to. When Steve takes it on the couch, he goes back to an early European settlement in Louisiana. However, when he takes it while standing up in his living room, it sends him back to Neanderthal times. 

Steve also realizes that objects you hold onto as you go back and forth through time travel with you. The woman who burned alive at the abandoned theme park held onto a doorknob, and that was with her at the crime scene. With this knowledge, Steve tries to determine whether you can bring living objects back with you, too.

In a future experiment, Steve attempts to figure out whether he can bring organic matter through time with him, no doubt trying to determine if he could simply hold onto Brianna to bring her back. He goes through with this experiment with his dog, Hawking. He hugs his dog tightly, bringing them both into the past — except this time, they've gone back to the most treacherous time possible for Steve.

They travel to the recent past when Steve's house is still standing. The only problem is that someone else is occupying the house, and they don't take too kindly to seeing Steve there. Steve and Hawking make a run for it when the homeowner pulls out a gun, and it's at this point Steve discovers something else strange about the pill. Seven minutes pass, and Steve and his dog haven't returned to the present. He realizes that you have to be in the same location you took Synchronic in order to leap back to your own time period.

Steve waits until night comes before heading back inside the house so that he and Hawking can sit on the couch again. He takes another pill and heads inside. The only problem is that he apparently didn't wait long enough because the homeowner returns and sees Steve and Hawking sitting there. They get into a tussle as Steve begins to fade back to the present, but Hawking is at the front door, away from Steve. When Steve returns to the present, he sees a ghost of Hawking there momentarily until he fades out of the present. 

Sadly, Hawking is trapped in the past since he wasn't touching Steve during the jump. There aren't enough pills for Steve to go back to try to get Hawking and rescue Brianna, so Hawking is stuck in another time period, hopefully doing all right.

At the beginning of Synchronic, the two paramedics see the impact of drug use. They witness horrific deaths that all seem to be connected with this designer drug. And that makes it all the more confusing to see the two main characters indulge in illicit substances. They both drink, and we even see Dennis popping pills. 

Both men are adrift in life. They're not really going anywhere, so they need a way to numb themselves to the day-to-day monotony of existence. Dennis' life is falling apart around him with a tenuous marriage on the rocks, a teenage daughter who's becoming more unruly, and a baby who's only making things more difficult. Steve engages in alcohol consumption and even one-night stands. 

It all has to do with the central theme of Synchronic. Both men just want time to stop, but it's moving forward regardless of what they try to do. The drug literally displaces people out of time — but really, that's what any drug does. Getting into a haze with drugs and alcohol allows time to stop, and you're not focusing on the ills of society and your own personal shortcomings because your mind is in another world. The same happens with Synchronic, and it's only through this drug usage that the men realize how important it is to live in the present and not try to escape.

Near the end of Synchronic, Steve finally learns where Brianna would have taken the drug and takes his second-to-last pill there. His hunch is right, and he's transported to what looks like a war zone. While it takes him a minute to find his bearings, Steve finally does come across Brianna, who's been hiding out in a trench. 

Steve gives Brianna his final pill and leads her to where she needs to be for the time jump to work properly. But things don't go smoothly when they learn they're not alone amongst the flames. A man appears, pointing a gun at Steve. He gets Steve to walk forward with his hands in the air, but Steve doesn't want to get too far away from the rock he needs to be at. 

The time for the leap comes and passes. Brianna goes back to her present and hugs her father. But what about Steve? We see the "ghost" of Steve, not being near enough to the rock to jump back to the present. He's stuck in the past, just like Hawking. All Dennis can do is go to Steve and shake his hand one last time before he fades away completely. 

It's a downer ending, but it's probably the one Steve would have wanted. He obviously won't get the treatment he needs back in the past, so his tumor will likely kill him within a matter of months. As the Synchronic ends, some viewers may wonder if there's any hope left for the paramedic. 

Don't hold your breath. 

Dr. Kermani made it explicit in his conversation with Steve that he retrieved and destroyed all of the remaining Synchronic, with the few pills Steve had being the last of the batch. Brianna took the final pill to return to the present, and in a quick blink-and-you'll-miss-it moment, we learn there's no way to get anymore. As Steve's driving, he listens to a news report on the radio about how Dr. Kermani committed suicide, likely haunted by all the people whose lives have been destroyed by the drug he created. There's no way to make any more Synchronic, and what did exist has been destroyed. Steve's stuck in the past, using what little time he had left to help his best friend and his family get one more chance for happiness.