You have not indicated which theme. I have rephrased the question to refer to several themes
Also note, this is a general response.
1. Death. This theme is brought out when Thoni tells the woman she longs for a country that is full of darkness. No one will be able to see another person in that dark country. And there will be no hurt. Darkness symbolizes death. She longs to be dead.
2. Superstition. An elder asks Nyobi to bless the traditional medicine so that it can be powerful to bring back Remi.
3. Racism. Omange narrating an incident of an African seen with an Indian woman. That African is criticized for being in a relationship with someone of a different color.
4. Religion Vs Politics. The leader telling the elders when Remi comes back, they should make sure he is not influenced by Christianity. Also, when the Pastor tells Nyobi when Remi comes back he shouldn't be influenced by the elders.
5. Wife inheritance. Remi's father cussing Remi for not accepting to inherit his dead brother's widow. Also, his mother pleading he does so according to the custom of Maria tribe. Also, the elders pleading.