The forbidden temperature.

The university master has almost 50 years since he left the country, and there's only him and the nurse's daughter-in-law who have long been lonely enough to take care of him, look at him, test him, step by step across the line that shouldn't have been touched, during the day and the night, and become the only exit for each other until he suddenly says that I'll be home soon, the door is still unlocked, and people are outside.