Sergio Marquina, also known as The Professor, is a fictional character from the Spanish television series La Casa de Papel (Money Heist). He is portrayed by actor Álvaro Morte and serves as the mastermind behind the heists in the series. Sergio is known for his intelligence, strategic thinking, and ability to stay calm under pressure. In the show, Sergio leads a group of robbers as they attempt to carry out complex heists on the Royal Mint of Spain and the Bank of Spain. His character is central to the plot, showcasing themes of loyalty, betrayal, and the moral dilemmas faced during the heists.