The music video, directed by Jamie Thraves ("Just
" by Radiohead, "I Will Follow You into the Dark
" by Death Cab for Cutie), is rather inventive, with all the action going backwards, apropos for a song about going "back to the start." It starts with Chris Martin lying on a mattress and plays in reverse as we see how he got there. We learn that he was driving on a country road with his girlfriend in the passenger's seat when he swerved to avoid another vehicle, sending their car careening down a hill. His girlfriend is tossed through the windshield and presumably dead, but Martin wakes up and wanders off, eventually ending up on the mattress.
The video was shot with the action moving forward, then reversed in post production. A key component is the lip-synch - making sure Chris Martin is singing normally in the finished product. To achieve this, he had to sing backwards so when the video was reversed, he'd appear to sing normally. This meant learning the song backwards, which took him weeks.
Spike Jonze directed a backward video for the 1996 Pharcyde song "Drop," but that one bent time and space by having the group move backward in sections. In the Coldplay video, everyone moves in the same direction.