A possible concise summary is:
The episode follows the lives of different characters in a Soviet outpost in Georgia in the late 1980s. Katia, a young nurse, arrives with her husband, a lieutenant, and tries to fit in with the locals. She meets Irina, the manager of an orphanage, and Ogniev, a political officer who is attracted to her. Irina has a complicated relationship with Kalinin, the outpost commander, who is married to Raya, a jealous and violent woman. Raya attacks Irina when she sees her singing with Kalinin at a concert. Ilya, a major, proposes to Irina, but she rejects him. Mitia, Katia's brother and an orphan, runs away from the orphanage and ends up in the line of fire during a military exercise. Katia drives an ambulance to rescue him, risking her life. Ogniev tries to stop her, but fails. The episode ends with a cliffhanger.
Here are the key facts extracted from the text:
1. A Korean nuclear fusion reactor achieved 100 million°C for 30 seconds.
2. The experiment demonstrated that nuclear fusion is moving from a physics problem to an engineering one.
3. The temperature achieved is nearly seven times hotter than the core of the Sun.
4. The core of the Sun has a temperature of close to 15.7 million Kelvin.
5. The surface temperature of the Sun is approximately 5800 K.
Please note that these are factual statements based on the information provided in the search results and do not include any opinions.