Guzmán begins to suspect Polo might have killed Marina, but Ander—burdened by the secret—lies to him to protect Polo.
If you are referring to a different series, here are other possibilities for a Season 2, Episode 7 titled around "Missing" or "Desaparecido": "Elite" 84 horas desaparecido (TV Episode 2019) - IMDb [S2E7] 84 horas desaparecido
At a charity fundraiser, a vengeful Lu publicly exposes Cayetana's deception. She also reveals that Samuel and Carla have been sleeping together and leaks a private video of Nadia and Guzmán. Guzmán begins to suspect Polo might have killed
Lu (Lucrecia) discovers Cayetana’s secret—that her mother is a cleaning lady at the school and Cayetana's wealthy lifestyle is a lie. [S2E7] 84 horas desaparecido
This episode is a major turning point that connects the flash-forward investigation of Samuel's disappearance with the events leading up to it.