In 2024, in Philadelphia, the city has become nothing but abandoned buildings and fires on
the streets. Not a single survivor can be seen around. In 1988, also in Philadelphia,
a mysterious hooded person walks through the city. Meanwhile, a pianist, a cook,
and a bus driver are going through their usual nights when suddenly, they begin bleeding from
all their orifices before they all die at the same time. The bus crashes and a book falls,
revealing the driver had been reading "American Patriot". Police officer Thomas is starting his
shift soon, but before leaving home, he cooks a quick breakfast for his pregnant wife Jean.
After meeting with his partner Maddox, they go to see the bus crash, where Thomas' brother-in-law
and head detective Holt is already working. When they look at the body, they find pieces
of the driver's brain on the ground and three weird puncture wounds on her neck. Afterward,
they check on the pianist and the cook, finding exactly the same situation: brain chunks and
three puncture wounds. Later, Thomas and Maddox go to see the doctor in charge of the autopsy,
who explains the wounds were injection sites deep enough to impact the vertebrate. However, nobody
in the lab can identify the poisonous substance used in this injection. Then, they go out to
grab a bite, and Thomas takes the chance to buy a bracelet for Jean. Their dinner is interrupted by
a call from a cop that has found another person with those three puncture wounds, but this one
is still alive. The pair rushes to the club, where Holt is coming for interrogation too, and
they learn that this girl has been attacked by a black woman with a blue hoodie and a bloody hand.
Before she can offer more information, though, she dies the same way all the others did. The police
force begins interrogating every black woman they can find and thanks to a few witnesses, they get
an identikit. Soon they find the area where the murderer was last seen, and Thomas and Maddox end
up coming across her by mere chance. Her name is Rya and she runs to hide in the subway station, so
the cops follow her there, missing when the radio in the car announces Jean is going into labor.
Thomas finds an empty futuristic weapon on the ground that looks like the thing Rya used for the
injections, but it's Maddox the one that finds her first. Rya easily fights him off and breaks his
leg before running off, but the noise they make is enough for Thomas to find them. He aims his gun at
her, only to freeze when she begins speaking mysterious words. Rya knows his name and says
"this is where it happens", she also congratulates him on his new daughter and apologizes for Maddox,
claiming she didn't mean to. Thomas doesn't want to hear it and tries to arrest her, but Rya fights
him off and handcuffs him to a bench. Remembering he still has her weapon, Thomas hits her with it,
and Rya falls back, dying when the train passes by. Taking the case as closed, Thomas leaves the
station and another officer tells him about his wife. Thomas rushes to the hospital, where he's
approached by another cop that tells him Rya had no ID or fingerprint matches, she was a nobody.
The only thing on her was some weird keys. The officer also asks Thomas for his revolver
because Rya had a bullet from a service gun on her hand, which is strange because none of the cops at
the scene of the crime fired their weapons. Then, Thomas is found by a nurse that tells him Jean is
having trouble giving birth and is hemorrhaging. Thomas rushes to her side and puts the bracelet
on her wrist, but his presence isn't enough. Moments later, the doctors bring Thomas and Holt
the news: the baby is safe, but Jean unfortunately died. Nine years later, in 1997, Thomas,
who is now a detective, has taken the day off to spend it with his daughter Amy on her birthday.
Amy has been wearing her mother's bracelet since she was a baby, and every year Thomas gifts her
a new charm for it. Their first stop is at the cemetery to leave some flowers on Jean's grave,
and Thomas is shocked to see someone had already been there and left flowers as well. Next,
they should be going to the zoo, but Thomas gets an emergency call and since it's so important,
he leaves Amy with another cop for a moment while taking a look at the latest crime. Maddox is there
too, walking with a limp now, and swearing he wasn't the one to leave flowers for Jean earlier.
The reason why Thomas was called is that another body with three wound punctures has shown up,
and since today it's the anniversary, it can't be a coincidence. This time the victim is a
professor of politics, and the weird poison has been used again, which is strange because not even
the police labs could figure out what it was. Holt, who is now lieutenant, shows up as well,
and after telling Thomas he didn't leave flowers for Jean either, they check the security cameras
and find a person wearing the same hoodie as Rya. The officers decide to blame it on a copycat,
but Thomas isn't sure and drags Amy with him back to the station to reopen the old case. They never
looked at the clues closely because with Rya dead, the case was closed, but now it's time to put the
puzzle pieces together. Thomas sends the keys they had found to be analyzed while he learns two more
bodies with the same wounds have been found, and he decides to stay at the station and work on the
case, so Amy's birthday outing is canceled. They can't find any connection among all the victims,
but Thomas begins to worry when he realizes the copycat has an injured hand like Rya,
yet they never made that detail public. The test results come in, showing that the keys belong to
an aircraft common in small airfields manufactured in 1996, which makes no sense because they found
these keys in 1988. Only one airfield in the area has that kind of plane, so Thomas leaves
Amy with an officer to go check it out. On his way out, though, he bumps into Doctor Rao,
who points out the case has some coincidences with his studies. The murders match a specific
lunar perigee known as a blood moon, which is theorized to open a bridge into time travel,
but Thomas and Maddox don't take him seriously. When they make it to the airfield, they find it
closed, but Thomas can see a light in the building and decides to sneak in anyway. The clerk denies
having seen anybody tonight, but Thomas can tell he's behaving awkwardly and nervously, thus
he tries to communicate with him through notes because he suspects he's being held hostage. His
guess is correct, but before he can do anything about it, Rya shows up next to him, alive and
not having aged a day. While pointing her gun at him, she makes Thomas drop the weapon, then orders
the clerk to tie him up. With the clerk between him and Rya as cover, Thomas takes the chance to
take out his phone and call Maddox so he can hear what's going on before he's tied up to a chair.
Next, Rya asks for plane keys, and when the clerk goes to grab them, he takes out his own weapon to
defend himself, except Rya is quick to act and knocks him out to grab the weapon for herself.
Suddenly, she's startled by Maddox showing up behind her and she accidentally shoots him,
killing him without meaning to, which explains the apology she gave Thomas nine years ago. A backup
party led by Holt is already arriving at the airfield, so Rya drags Thomas away with her in a
plane. Thomas passes out and dreams of Jean before Rya wakes him up to tell him to stop chasing her
because she's doing all this to save people's lives. The reason why she's alive is that every
nine years when the moon sets, she can come back, but not for long. She doesn't want to explain more
because Thomas needs to stop and go back home to his daughter, but since he refuses, Rya pushes
him out of the plane and into the water. Thomas swims to the shore and finds the crashed plane,
yet no Rya in sight. In the morning, after Holt scolds him for being reckless, Thomas tells
him they won't find Rya's body because she's most likely a time traveler from the future.
Nine years later in 2006, Thomas is digging out the grave of a man called Harold Nowak,
whose death had been dismissed as an addiction but Thomas now finds the three wound punctures on
his skeleton. He has become so obsessed with this case that he left the force and became a private
investigator to figure out the mystery behind Rya; he lives in his car and has a radio hooked to the
police force's frequency in order to keep an ear out for any clues. Thomas has also begun reading
about the Moon and its energies while looking for Doctor Rao, but he's completely disappeared. After
checking Nowak's name on a list, Thomas visits the widow, who tells him Nowak used to run a white
nationalist militia group. Nowak's ex Heather used to work with him, so Thomas writes her name
down before asking for a list of the members of this group. This list is the connection he's been
missing because on it, he finds the names of many of Rya's victims. Afterward, Thomas goes to pick
Amy up at school. Nowadays she's living with Holt and his wife and she doesn't see her father much,
in fact, she disapproves of this lifestyle of his. Still, she tries to tell her about
any news in her life, including the mention of a boyfriend that Thomas doesn't remember even if
he's met him before. Then, Thomas drops Amy at her home, but not without giving her a birthday
present, which is another charm. Unfortunately, Amy stopped wearing the bracelet ages ago,
and Thomas didn't even notice. Next, Thomas visits Jean's grave before getting together with Holt at
a cafe to show him the new clues he's found. Thomas thinks Rya is killing all the members
of this group with an advanced poison from the future that can be activated remotely,
and she's moving backward in time while the rest of the world moves forward, which explains why
Thomas saw her die and then reappear just fine, and why she had that information about him Thomas
just wants Holt to help him get Heather's address, but Holt thinks he's crazy and dismisses the
time-traveling theory. Not willing to give up yet, Thomas pretends to cry and accept he's in a bad
mental health state, apologizing for his actions. Holt hugs him and promises to help him find a
therapist, and Thomas takes the chance to steal his badge. Once Holt is gone, Thomas pretends to
be him and calls the station to ask for Heather's information from the system. Unfortunately, by the
time Thomas makes it to Heather's place, she's already dead, and she's got the same bleeding
and three wound punctures. Suddenly, Rya jumps out of the house and Thomas tries to shoot her,
wounding her hand with one of his bullets as it was previously found on her dead body. Rya escapes
on a bike, so Thomas steals a truck and follows her to the same beach where she had crashed the
plane. By entering a sewer pipe, Thomas finds the place where Rya hides her time machine, but before
he can do anything, she actives it and gets away. When Thomes leaves the sewer, Holt and his men
are waiting for him to arrest him, not believing his crazy story about a time traveler. From afar,
Rao watches this whole scene happen. Nine years later in 2015, Rao has finally finished working
on the poison that would later be used by Rya by testing it on pigs. Thomas had been right, it's
activated remotely from a computer, which explains why all the victims die at the same time. His lab
is near the same shore with the sewer pipe, and the security cameras show him that today, Thomas
is making camp at the beach because he knows it's the anniversary and Rya should be coming. While
waiting, Thomas gets a call from Amy, telling him that even if they barely see each other nowadays,
she'd like him to be there when she has her baby. He barely has time to think about what to do when
suddenly, his face is covered and he's knocked out. When he wakes up, Thomas finds himself in
Rao's van with all the dead pigs. Rao himself is driving and explaining that it's thanks to
Thomas' investigation that he understood Rya is saving the world and she's the culmination
of his own research. He'll be keeping Thomas locked for a few days so Rya can do her thing,
then Rao promises to let him go. Thomas doesn't accept this plan, though, and he jumps on Rao to
try to make him stop the van. Instead, the vehicle ends up crashing and Thomas gets to run away.
A few moments later at the beach, Rya shows up after time traveling for the first time,
and Thomas is there waiting for her. He intends to kill her so she can't keep traveling back,
that way the murders won't happen and he won't become this obsessed shell of a person. Rya
explains he won't do that because she's known him her entire life, in fact, Thomas was the one that
told her to take this job. Then, Rya takes off her bracelet, revealing she's Thomas' granddaughter,
explained by the fact Amy married a black man. Thomas puts his gun down and asks Rya to stop
him from killing her in the past, but she can't because it's already happened and time traveling
is a one-way trip. Then, Rya asks Thomas to go home and spend time with Amy while she finishes
her mission. It all started when Rya was nine and a man detonated a van with explosives that
killed eleven thousand people. This triggered a series of events that ended in a civil war that
killed millions and left the country in ruins. That's why Rya volunteered to go back and shoot
all the members of the militia group with the doctor's special poison, which is activated by
an old Rao in the future, resetting the whole timeline. In the present, Thomas makes it to
the hospital just in time, and Holt is glad to see he's finally chosen family over work. Thomas
gets to hold the newborn Rya for the first time, and he puts the bracelet around her tiny wrist.