Nicholas Sparks's novel
John Tyree (Channing Tatum), a young Seargeant from the Army Special Forces, is lying on the ground in his combat gear with multiple gunshot wounds on his body. Coins begin to fall over him as he recalls a childhood trip to the U.S Mint. He goes on to compare himself to a coin in the United States Military and states that the last thing he thought about before he blacked out, was "You."
In 2001, John is on leave when he meets Savannah (Amanda Seyfried), a college student on spring break. In a matter of days, Savannah and John fall in love. John meets Savannah's family as well as her neighbor, Tim Wheddon (Henry Thomas) and Tim's autistic son, Alan (Braeden Reed), who looks up to Savannah.
Savannah meets and befriends John's father, a reclusive man who is only interested in his coin collections. John tells Savannah that his father has always been obsessed with coins and has not been much of a father to John, whose mother is not in the picture. Savannah mentions to John, that his father, like Alan, may have autism. This upsets John, who believes Savannah is calling his father retarded. He is so caught up in his anger that he gets into a fight with Savannah's rich neighbor, Randy (Scott Porter), accidentally punching Tim in the process. John apologizes to Tim the next day and leaves Savannah a note, seeking her forgiveness before his leave comes to an end. Savannah gets the note, and they spend one last day together. John returns to the Army and he and Savannah begin a long-distance relationship through handwritten letters. John believes that year will be his final year of enlistment but, following The September 11 attack , is torn between returning home and his sense of duty. He is given a weekend off, which he spends with Savannah and her family as well as with his father. He asks Savannah for her opinion on whether or not he should re-enlist, and she tells him to do what he feels is right. Like the rest of the soldiers in his unit, John chooses to re-enlist.
Over the next 2 years, John faces dangerous missions and begins to live almost entirely for Savannah's letters. John and Savannah find themselves drifting apart. Finally, Savannah, sad but resigned, sends John a Dear John letter informing him that she has become engaged to someone else. John, deeply depressed and frustrated by the news, believes she is engaged to Randy. On a mission, he enters a dangerous area and is shot several times by an enemy, which bridges back to the first scene of the movie. After recovering from his wounds John's Captain suggests that he go home and spend time with his father but, still upset about Savannah, John chooses to re-enlist again. He decides that he will make a career out of the Army and stay enlisted for as long as possible.
For the next four years, John, trying to mend his broken heart over Savannah, takes part in many missions with his new unit, spanning from the early years of the invasion of Iraq to the current resurgent conflicts in Afghanistan. While waiting to receive orders on his unit's next deployment at their regional operations base in Qatar, John is informed that he is being sent home for the first time in six years, because his father is dying. When John arrives at the hospital the doctor informs him that his father suffered a severe stroke and was not found until days later. John feels guilt that if he had been there, the outcome for his father would have been better. The doctor assures him that his presence and quicker medical attention would have done little to help his father due to the severity of the stroke. John spends the last few days of his father's life by his side and writes him a letter. His father has difficulty opening it, so John reads it to him. It is then that the viewers find out that John's speech at the beginning of the film addressed his father, not Savannah. He tells the story of the first mule coin, that he found and how it brought father and son to a shared passion of coin collecting. They connect in a tearful moment, and his father dies soon thereafter.
John goes to see Savannah. He discovers that she married Tim, not her rich friend. Savannah tells him Tim has cancer and is not allowed to leave the hospital. She says that the only way he can come home is by having an experimental drug that they can not afford. John visits Tim in the hospital, where Tim apologizes to John. He confesses that he has always loved Savannah and that he is happy because his son Alan will always have someone to care for him. Tim also admits that Savannah still loves John. While he wishes that she loved him the same way, he accepts what can never be. Late that evening, after reconnecting with Savannah, John finally says goodbye to her, forcing Savannah to acknowledge that she has lost John, bringing her to tears.
John sells his father's coin collection, though he keeps the very first mule coin that was the key element to their bond when he was a boy. He anonymously donates the money from the sale to finance Tim's drug. The next scene shows John back with his unit, using the mule coin in a coin toss with his fellow soldiers. John then gets an unexpected letter from Savannah. She writes about how she received an anonymous donation to help Tim with his treatment to buy him time to say goodbye and thanks him for doing so. Tim died after two months. She expresses that she still wonders where John is and what he is going through, but she accepts that she lost the right to know a long time ago.
Moved by Savannah's letter, John gets a new lease on life and decides to leave the Army after his current tour. In the last scene of the film, John walks a bicycle down a block in an American town and stops to chain it up. At that moment, Savannah in a nearby cafe turns to spot him. John turns, and they lock eyes through the cafe's glass window. Savannah exits the cafe, and they embrace with passion.
