Cwmtaff incident

The Cwmtaff incident was the name given by The Secret Lives of Monsters to the event in which Silurians were encountered by humans in Cwmtaff in 2020. (TV: The Hungry Earth/Cold Blood, PROSE: The Secret Lives of Monsters) Having become involved in the event, Eleventh Doctor identified it as a "temporal tipping point", explaining that it was not a fixed point in time. He claimed that such a tipping point would "change future events, create its own timeline, its own reality." (TV: Cold Blood)

Aftermath
Ten years after their visit to Cwmtaff, Amy and Rory, now living in 2020, returned to wave at their past selves from a distance. (TV: The Hungry Earth) The erasure of Rory by the crack resulted in Amy losing her memory of him as, despite being a time traveller, Rory was tied to her personal history. The change in history was visible when, upon the Doctor and Amy's return to the TARDIS, they saw the future Amy now alone. The piece of the outer plasmic shell retrieved from the crack by the Doctor alerted him to the future destruction of the TARDIS, (TV: Cold Blood) in the Total Collapse Event Incident. It was during this incident that Rory returned as an Auton Roman replica, later known as the Last Centurion, created as part of the Alliance's ill-fated attempt to prevent the total event collapse. The Auton Rory, along with Amy and River Song, assisted the Doctor's efforts to reboot the universe, after which Rory, again a living human, was wed to Amy, retaining his memory of having been "plastic". (TV: The Pandorica Opens/The Big Bang)