The song was written by Tom Odell and Rick Nowels.
[1] The video, like the song itself, expresses the protagonist's frustrations about being attached to his significant other that doesn't reciprocate the same kind of love.
Odell was interviewed by Fuse regarding the concept of this video and its link to his previous single "Wrong Crowd" saying, "Magnetised very much hits into this idea of sort of “man vs. nature”: you have a cheater and you have a fast car and it’s like interesting, playing on that idea between the two of them.
So he’s destroyed this relationship, you know, with a woman, and at this point he’s now realizing that she’s no longer available to him–and he can’t give it up.
There’s a lyric in it called “I wish I had a little mother nature in me” which is kind of around the theme of the song of, he just wants a relationship which feels natural rather than this sort of perverse, poisoned situation he seems to be in, and Magnetised plays on that theme.