While it's possible that the song truly is only about the Bermuda Triangle, I think that Welch, who in the tradition of Steely Dan enjoyed combining jazz melodies with poetic and cryptic lyrics, meant for it to have a deeper meaning. In this case, I think the song is about the feeling of neurosis that disrupts us whenever something new and unexplained comes into our lives, Welch makes this a feeling that we can all identify with, "they come from Mexico, it does matter where."
While it's possible that the song truly is only about the Bermuda Triangle, I think that Welch, who in the tradition of Steely Dan enjoyed combining jazz melodies with poetic and cryptic lyrics, meant for it to have a deeper meaning. In this case, I think the song is about the feeling of neurosis that disrupts us whenever something new and unexplained comes into our lives, Welch makes this a feeling that we can all identify with, "they come from Mexico, it does matter where."