The film is set in the charming city of Hudson, Ohio, where Scott "Scotty" Thomas (Scott Mechlowicz) faces heartbreak when his girlfriend Fiona (Kristin Kreuk) dumps him right after their high school graduation in 2004. That evening, he and his best friend Cooper Harris (Jacob Pitts) attend a graduation party. Here, a live band performs a song that painfully narrates Fiona's affair with the band's singer, who happens to be Matt Damon.
Returning home drunk and furious upon discovering Fiona's infidelity, Scotty reads a heartfelt email from his German pen pal, Mieke (Jessica Boehrs), whom he nicknames "Mike." Mieke expresses her sympathy and suggests meeting in person. However, Cooper warns Scotty that "Mike" could be a sexual predator, leading Scotty to tell Mieke to stay away. His younger brother Bert later clarifies that "Mieke" is a typical girl’s name in Germany, awakening Scotty's realization of his true feelings for her. When Scotty attempts to reach out again, he discovers that Mieke has blocked his email. Driven by regret, he decides to embark on a journey across Europe to apologize, ignoring the summer job he had promised his father.
Together with Cooper, Scotty opts for the Midnite Express service, which offers cheap tickets—as long as they carry assorted packages. Unfortunately, there’s no route to Berlin for a week, prompting them to opt for lower-priced flights to London. Upon landing in London, they encounter a rowdy group of Manchester United soccer fans led by Mad Maynard. The duo ingratiates themselves with the fans and, after a night of revelry, they find themselves on a bus heading to Paris the next morning.
In Paris, Scotty and Cooper reconnect with classmates Jenny (Michelle Trachtenberg) and Jamie (Travis Wester), fraternal twins traveling across Europe. Eager to find Mieke in Berlin, they decide to make some stops to explore along the way. First, at Crans Sur Mer, they forsake their planned visit to a local monument for a nudist beach, only to discover it’s crawling with men, while the women have retreated to a nearby hidden beach.
Their adventures continue in Amsterdam, where misfortune strikes when Jamie is robbed while being intimate in an alley, leading to the loss of their money, passports, and train tickets. Their attempts to hitchhike to Berlin misfire due to a language barrier, landing them instead in Bratislava. Here, buoyed by a favorable exchange rate, they indulge in the nightlife. Under the influence of absinthe, Jamie and Jenny share an unexpected kiss, much to Scotty and Cooper’s shock.
The following day, they manage to secure a ride to Berlin, only to find that Mieke is currently touring Rome with a summer group. Desperate, Jamie sells his prized Leica camera for plane tickets to Rome. Upon their arrival, they search for Mieke in the magnificent Vatican City. However, amidst their attempts to connect, Scotty accidentally rings the bell signaling the Pope’s passing, leading to a comical series of events where he unwittingly appears on the papal balcony, mistaking crowds for Mieke below.
With the help of their Manchester United friends from London, Scotty finally meets Mieke and confesses his feelings. Their reunion culminates in an intimate moment in a confession booth just before her departure. As Scotty and his friends make their way back to Ohio, Cooper and Jenny give in to their urges, while Jamie, having impressed travel legend Arthur Frommer, decides to remain in Europe to enrich his travel guidance contributions.
The film wraps up with Scotty settling into Oberlin College in the fall. During a phone call with Cooper—now dating Jenny—Scotty is surprised to find Mieke knocking on his door, mistakenly assigned to the same room due to another mix-up. The story concludes with Scotty and Mieke embracing their new beginning together.
