Šifra - Unikla sériovému vrahovi. Ten se pro ni teď vrací… – Maldonado Isabella (2021)

At sixteen, Nina Guerrero managed to escape the deadly trap of a serial killer. Eleven years later, she is an adult woman, a special FBI agent who won't take anything lying down – and after a video goes viral showing her effectively dealing with attackers who assaulted her in a Virginia park, she gains legions of fans. But someone else is watching. Someone who cannot forget an old grievance against Nina. Determined to punish the one who got away, a killer from Nina's past commits a brutal crime just to pull her into the investigation. However, his game is just beginning. And thanks to the internet, more people than ever are getting involved this time. His riddles and wordplay may have made him a twisted social media star – a mysterious virtual ghost nicknamed Cipher – but to Nina, he is still what he once was: a monster feeding on the suffering of the weak. To catch him, she must team up with FBI colleague, psychoanalyst Dr. Jeffrey Wade. He too is haunted by shadows from the past, but only together do they stand a chance – clue by clue, victim by victim – to find the cold-blooded killer. A race against time begins, watched by the whole world.