In a Glass Cage (Spanish: Tras el cristal) is a 1986 Spanish horror film written and directed by Agustí Villaronga, and starring Günter Meisner, Marisa Paredes, and David Sust. Inspired by the history of Gilles de Rais, the plot follows an ex-Nazi child molester who is now paralyzed and depending on an iron lung to live. A young man claiming to be his new caretaker reveals himself as one of the Nazi's former victims, and forces him to watch while he re-enacts his tormentor's crimes.

Due to themes mixing Nazism, pedophilia, torture, and homosexuality, the film was highly controversial. To celebrate the 30th anniversary of the Teddy Awards, the film was selected to be shown at the 66th Berlin International Film Festival in February 2016.