While I can’t speak for its scientific documentation, cryptophasia, the secret of language of twins, fills our home. Jen and I sometimes move to an adjoining room to watch Amelia and Olivia banter, coded words bubbling past their lips. What is strange to our ears is familiar to theirs. In Tournier’s novel, the twins call their “unfathomable jargon” Aeolian, suggesting their words are like wind. Their shared speech “enabled us to talk together for hours on end without others present being able to understand a word we said.”