In the snowy hills of Sweden, former assassin Jack is spending time with his girlfriend Ingrid while
trying to keep his old life behind, which Ingrid doesn't know about. One morning, they go out for
a walk and find footprints in the snow. Ingrid thinks it may be hunters, but Jack knows better
and gets suspicious, so he drags Ingrid into a hiding spot just in time before someone begins
shooting at them from the woods. Jack shocks Ingrid by revealing he has a gun and uses it to
kill the attacker with one accurate shot. The body falls in front of them and Jack begins searching
it while telling Ingrid to go to the house to call the police. As soon as Ingrid turns around though,
Jack kills her too because he knows his identity has been compromised. Nearby, there's a car with
another assassin waiting for his partner, but Jack finds him and kills too. Afterward,
Jack hurries to leave the country and makes his way to Rome, Italy, where he meets with his
handler Pavel. Jack explains he was found by the Swedes and that Ingrid had nothing to do with it,
but Pavel still believes she could've set him up and reminds Jack he shouldn't make friends
in this line of work. Pavel will take care of the people that found Jack, but meanwhile
he can't stay in such a big city, so he's made arrangements for Jack to stay in Castelvecchio,
a very small town on the map. Using the car Pavel prepared for him, Jack travels to Castelvecchio,
but he hates it as soon as he arrives for being so small and boring. Jack decides to turn the car
around, throw away the phone Pavel got him, and go to Castel del Monte, a more active town. Here
he rents a very humble apartment and adopts the name Edward, but most of the neighbors
call him "The American". Jack starts a daily routine of exercise, visiting the local café,
and bringing his camera to natural places because he's pretending to be a photographer. Although
he's living a peaceful life now, Jack still keeps an eye out for any danger that may follow him,
using binoculars to watch Castelvecchio in case anyone is looking for him. This constant alert
means Jack can't help but be startled whenever the neighbor's scooter makes a gunshot-like sound. One
morning, Jack's having trouble using a vending machine and is approached by Father Benedetto,
who helps him out after Jack says he isn't good with machines. Benedetto asks a bunch of questions
to get to know him better and invites him to drink wine at his house later, Jack tries to
turn him down but Benedetto reminds him priests see everything. Afterward, Jack uses a payphone
to finally call Pavel, who is furious with him for ditching the cell phone. Pavel still offers Jack
a job, which would consist of making a custom fit for a fellow assassin, meaning Jack won't
have to kill anyone. Jack promises to think about it. In the evening, Jack goes to see Benedetto
for that drink. Benedetto is surprised that if Jack is photographing Italy he isn't learning
about the country's history, then he points out it's probably his American nature that makes him
think he can escape history and only live in the present. Sometime later, Jack drives to Sulmona,
where he does some shopping and watches Mathilde from afar. When she sits at a café, Jack takes the
table next to her and picks up her newspaper when she drops it as a sign he's the gunsmith she's
looking for. Mathilde gives Jack all the details she needs for her weapon and Jack accepts the job,
he also points out there's been a guy watching them, but Mathilde swears she's working alone.
Later when Jack returns home, he thinks he sees the same guy in town and does his best to avoid
him. At night, Jack begins having trouble sleeping, reacting to any noise he hears by
taking out his gun. A few days later, Jack goes to the post office to pick up a very special package,
it's the pieces he needs to start working on the weapon. The first half of the assembly goes well,
but he's going to need some extra things to build a silencer. When night falls, he decides to visit
a bawdy house and meets Clara, a call girl that rocks his world. Sometime later, Jack
helps Benedetto fix his car when it breaks down in the middle of the road. The priest thanks him by
inviting him to dinner at his house, and Jack gets to hear Benedetto's stories about his relationship
with the townspeople. He has a picture of Fabio, the local mechanic, who Benedetto worries about
because he's a good man but he may be involved in some illegal things. Jack wonders if Benedetto
ever wanted to be anything other than a priest, and Benedetto sarcastically wonders if Jack ever
was something other than a photographer. Jack had told him he wasn't good with machines yet he fixed
Benedetto's car with ease, not to mention he can tell Jack has more money than a journalist should
make, but Jack doesn't raise to the bait. The next day, Jack breaks his car on purpose and takes it
to Fabio's garage. Fabio at first doesn't want to help a mysterious foreigner, but he changes
his mind when Jack mentions he's a friend of Benedetto. Jack explains cars are a hobby for him
and wonders if he could get some pieces to fix a broken drive shaft, and Fabio accepts to give them
to him for free. While Jack looks around to find what he needs to make the silencer, he discovers
Fabio has a copy of the same photograph Benedetto had. On his way home, Jack sees Clara going to
church and can't help sharing a flirty look with her. As soon as he gets to his apartment,
Jack begins working on the weapon again, finishing the silencer successfully by the time night falls.
The next day he takes the rifle to the woods and tests it to confirm it works perfectly.
Later Jack goes to the bawdy house to celebrate, but Clara isn't working today and Jack decides to
leave instead of choosing a different girl. In the evening, Jack goes to a café and notices the same
guy is still watching him. The clerk brings Jack an envelope someone left for him, and inside Jack
finds a newspaper clip talking about the bodies he left in Sweden. When he returns to his apartment,
he decides to take a different road just in case and keeps his gun extra close when he goes to bed.
Sometime later, Jack goes to the train station to pick up Mathilde, who is wearing a different wig
to protect her identity from curious eyes. Then he drives her to a secret spot in the forest near
the river that he's sure only he knows of, but Mathilde still wants to walk around and check
there aren't any footprints or tire tracks before they get to work. Afterward Jack puts down a
picnic blanket to use as a cover in case the cops investigate the area later and shows Mathilde the
rifle he's made. Mathilde puts it together like an expert and places an order for special rounds
made with mercury. She's brought her own target to test the rifle, which she does with no trouble,
then she asks Jack to shoot at the flowers next to her from a fair distance. Jack is surprised
that she trusts him enough not to kill her and shoots the flowers without even making her flinch,
impressing Mathilde with the silencer he made because she couldn't tell where the bullet came
from. Once they're done, Mathilde asks for some last adjustments and for the delivery
to be made by the first of next month as she pays the first half of the money. The bullet
cases are thrown in the river, and Jack throws some wine on the grass as part of the cover,
he even took the time to chill it because that's how it's drunk here. At that moment,
a butterfly lands on Mathilde's arm, and Jack tells her some cool facts about that specific
type. This makes Mathilde call him "Mr. Butterfly" and asks if Jack ever brought a woman here before,
which he denies. In the evening, Jack goes stops by the bawdy house to have some fun with Clara,
who also calls him "Mr. Butterfly" because of his tattoo. Clara can tell Jack has something
in his mind, but Jack doesn't think her worry is sincere and explains she doesn't have to act for
him as she does for other clients. He also tips generously, and when Clara points out she makes
more with him than all the other girls together, he confesses he doesn't see the other girls. Jack
continues to work on the modifications for the rifle and the bullets with mercury, but
he also takes breaks at the café. One afternoon, he comes across Clara, who is going to the movies
with her girlfriend. They do some chitchatting and Clara points out she's free on Wednesday,
so Jack says they can meet at the usual place. Clara tries to get him to mention what the "usual
place" is, and when he doesn't dare to mention the bawdy house in front of her girlfriend,
Clara takes advantage of this and asks him to meet her at a restaurant. After the ladies are gone,
Jack opens the newspaper and worries when he reads about call girls getting killed. Later that night,
Jack is making his way home and notices the usual guy isn't just watching anymore,
he's now actually following him. Jack hides in an alley and takes off his shoes while waiting for
the guy to pass by, then he starts following him with his gun out. His intention is to kill him,
but his plan is interrupted by the sudden arrival of the neighbor on his scooter, alerting the guy
of their presence. The assassin immediately reacts by shooting the driver and running away in his
car, so Jack takes the keys from the body and uses the scooter to follow him. A chase begins
throughout town as Jack tries to kill this man, but he keeps failing his shots. When they make it
to the road outside town, Jack finally manages to hit a tire and make the car crash. Then Jack comes
closer to kill him by hand and takes away his gun. Afterward, Jack calls Pavel and tells him the
Swedes have found him again, but Pavel tells him to stay put and finish the job. Jack wants to know
how he's been found and Pavel just responds Jack is losing his edge. That night, Jack has trouble
sleeping because the guilt of killing Ingrid keeps haunting his dreams. He decides to go for a walk
even if the sun is barely out and bumps into Benedetto, who likes to take morning early walks
to thank God for everything and ask him to look after those who are sinners. Jack points out all
men are sinners, prompting Benedetto to explain those who seek peace are much sinning in history,
and that Jack has done lots of sinning. Benedetto heard about the death that happened nearby last
night and wonders if Jack needs confession, but Jack turns him down and taunts him back
by confessing he can tell Fabio is Benedetto's secret son. Benedetto admits he made a mistake in
the past, but at least he has someone in his life, unlike Jack. In the evening, Jack meets with Clara
at the restaurant. He's very impressed by how she handles the waiter when he tries to take the order
from Jack instead of Clara because of her gender, and when a flower boy comes by, Jack buys her a
flower. Clara protests because the seller thinks they're a couple, but since Jack buys it anyway,
she sees it as a good sign. She can tell Jack has some sort of secret, but Jack denies being
married, so that's good enough for her. After dinner, they go to Clara's apartment and spend
the night together. The next morning while Clara showers, Jack snoops around and finds a gun inside
Clara's purse, making him suspicious. Later that day, he finishes the order and buys a suitcase
together with a bunch of office supplies to hide the rifle properly. Now that his job is done he
can go out and follow Clara around to make sure she isn't a spy. He does see her with some men,
but he can't tell if they're clients or criminals. The following day, Jack calls Pavel and asks for
two more days before making the drop, which Pavel grants. In the afternoon, Jack takes Clara to
the secret spot in the forest for a picnic. As soon as Clara sees the river, she takes off her
clothes to go swimming, but Jack doesn't join her. Clara also finds the bullet cases in the water,
but she blames them on hunters and Jack just throws them back. While they enjoy the picnic,
Clara reaches into her purse, causing Jack to tense and grab his gun to defend himself. It turns
out Clara was just grabbing her sunscreen, but his reaction triggers an argument anyway. Clara
explains she has a gun to protect herself because there's a killer going after call girls, and Jack
accepts to trust that explanation. Then Clara asks him to come with her to the town procession
tomorrow, and when Jack says he'll think about it, Clara wonders if they can start going on dates all
the time. Jack immediately shuts down the idea explaining he can't stay forever, prompting Clara
to kiss him and beg him to stay. Jack can't stop thinking about Clara's request when he goes home
and decides to call Pavel to inform him that after he does the delivery, he's out. Pavel seemingly
accepts this with no trouble, but after Jack hangs up, Pavel calls Mathilde with a special request.
The next day, Jack drives to a café by the road to meet with Mathilde, who is wearing a different
wig again. He hands her the mercury bullets in a special can, and Mathilde grabs the suitcase too
while excusing herself to go the bathroom, where she prepares an extra gun she brought with her.
Jack notices Mathilde is taking too long and the other clients have left, so he's anxious
and alone. With the gun ready in his pocket, Jack decides to wait outside just in case, and Mathilde
brings him the rest of the money. It looks like she's got more to say, but at that moment a bus
full of children arrives, and Mathilde leaves before they can be noticed. Jack drives back
to town and Mathilde follows him while talking on the phone to Pavel, who wants her to kill Jack as
soon as possible. Back in town, the procession is keeping the streets crowded, thus it's easy
for Mathilde to sneak inside a house, kill the owners, and find a spot on their roof to keep
an eye on Jack while Pavel also arrives in the area. Jack meets with Clara and asks her to run
away with him, Clara obviously accepts and they confess their love for each other. At that moment,
Mathilde gets ready to shoot Jack, but her weapon backfires and kills her because Jack had rigged it
in advance. Jack sees this and understands they're after him, so he hands Clara the money and tells
her to wait for him at the secret spot in the forest. Then Jack goes to check on Mathilde to ask
her who sent her, Mathilde confesses it was Pavel before she dies. Suddenly Benedetto arrives to see
what's going and Jack points his gun at him, but he's learned his lesson with Ingrid and doesn't
shoot. After apologizing to the priest, Jack goes looking for Pavel, entering an empty alley on
purpose so he'll be followed. Pavel falls for the bait and comes closer, but when he raises his fun,
Jack turns around and shoots until he kills him. Afterward, Jack takes his car to go to the forest,
but he starts feeling unwell when he realizes Pavel did hit him and now he's slowly bleeding
to death. Jack still tries his best to reach the forest and sees Mathilde waiting for him,
causing him to desperately reach out for her but dying before he can say good bye.