"The Guests" was an episode of the 1960s tv-series The Outer Limits. What makes this episode exceptional is its multiple layers from which so many interpretations can be drawn, among which is the ideation of suicide. Basically it's about humans who are trapped inside a mansion by an alien-creature who observes them to determine the so-called "human equation." Along the way, I notice the characters showing suicidal ideation, which I'll explain.
At first glance,the humans appear to be captives. But they are actually "guests" because the alien tells them that they are free to leave at any time. At the ending, when the alien has solved the "equation," he destroys the house and all those people inside.
As the mansion is being destroyed and the occupants die, if you notice Ethel Latimer, she is actually laughing. In other words, it obviously appears that Ethel feels jubilant at her death. Why else would she be laughing?