Julie left this in the comments and, as somebody who did not see this show from the beginning, I thought it was very helpful so I'm putting it out here in the open:
The man in Ariel's office was Conceptos's long-lost CFO, Olarte. He and Alicia once schemed together to get Lety fired by fiddling with Lety's computer, but Olarte got fired instead. Then Olarte and Ariel (and possibly Alicia?) worked together to get Lety fired over the kickback that had been offered to Lety in exchange for doing business with a company that was offering the lowest bid anyway... Lety confessed to Fern about the kickback before Ariel could tattle on her, and they used the kickback money to create Filmo-Imagen.
Julie, or somebody - could you explain why Conceptos is in such a mess that it needs the books doctored? And why does Fern keep saying it's HIS money that started Filmo Imagen?