"We have to grow up eventually."
When the Doctor returned to Leadworth after twelve years, he is accidentally introduced to Rory, Amy's long-term 'sort of' boyfriend.
Working as a nurse at the local hospital, Rory's ideal life would be to settle down in the village with Amy and start a family, so he is initially concerned when he discovers that her old 'imaginary friend' is back on the scene.
Two years later, on the night before their wedding, Amy steps inside the TARDIS, and, unbeknownst to Rory, has several adventures before the Doctor decides to return her to him during his stag night. In an attempt to rekindle their relationship, the Doctor takes them on a romantic mini-break to Venice in 1580, where a dangerous encounter with the fish-like Saturnynians allows Amy to see just how important Rory is to her, and she subsequently invites him to join them on their travels permanently - an offer Rory accepts.
It is during a battle with the Silurians that Rory is shot dead and absorbed into a crack in time, which erases him from history as well as from the memories of all who knew him, thus Amy continues to travel with the Doctor remaining blissfully unaware that she was ever engaged. At the opening of the Pandorica, they are reunited when it is emerged that the Alliance have created an Auton duplicate of him as part of their trap to capture the Doctor. As Rory failed to fight off the Nestene Consciousness, he shot Amy, and, when she was placed inside the Pandorica to be resurrected, he single-handedly guarded the box for over a thousand years, becoming known throughout history as The Lone Centurion.
With the universe restored, Amy and Rory finally married before rejoining the Doctor in the TARDIS for more thrilling adventures through time and space...