Introduction:
The phrase "From fog to endless night" is a metaphorical expression that represents the dark and uncertain future of slum children from birth to death. It portrays the bleak circumstances and lack of opportunities that these children face throughout their lives.

Explanation:
1. Metaphorical meaning: The phrase is a metaphor that compares the journey of slum children to a transition from fog to endless night. It signifies the transition from a state of confusion, obscurity, and hopelessness (represented by fog) to a future filled with darkness and uncertainty (symbolized by endless night).

2. Dark and uncertain future: The phrase suggests that slum children are born into a world of poverty, deprivation, and limited opportunities. They face numerous challenges such as lack of access to education, healthcare, and basic amenities. As a result, their future is characterized by uncertainty and despair.

3. Lack of opportunities: Slum children often lack the resources and support necessary to break free from the cycle of poverty. They face significant barriers in accessing quality education and are often forced into child labor or other exploitative situations. The phrase highlights the limited opportunities available to these children, trapping them in a perpetual state of darkness.

4. Social inequality: The phrase also reflects the stark social inequality that exists in society, where some children are born into privilege and abundance, while others are condemned to a life of hardship and struggle. It emphasizes the stark contrast between the bright future that some children may have access to and the bleak future that slum children are likely to face.

5. Impact on slum children: The phrase 'From fog to endless night' encapsulates the psychological, emotional, and physical toll that poverty and deprivation have on slum children. It represents the loss of hope, dreams, and aspirations that these children experience as they navigate through life without the necessary resources and opportunities to thrive.

Conclusion:
In conclusion, the phrase 'From fog to endless night' represents the dark and uncertain future of slum children from birth to death. It symbolizes the lack of opportunities, social inequality, and the emotional and physical toll that poverty and deprivation have on these children. It serves as a stark reminder of the urgent need for social and economic reforms to address the plight of slum children and provide them with a brighter and more promising future.