Rick Riordan said this quote
“ When Nico had woken up at Barrachina and found the Hunters’ note about kidnapping Reyna, he’d torn apart the courtyard in rage. He didn’t want the Hunters stealing another important person from him. Fortunately, he’d got Reyna back, but he didn’t like how brooding she had become. Every time he tried to ask her about the incident on the Calle San Jose – those ghosts on the balcony, all staring at her, whispering accusations – Reyna shut him down. ”