This short story is part of The Expanse series, providing the backstory for Amos Barton in a Baltimore-noir setting. Being a backstory, it doesn’t really add to what we know about Amos or his character. It does tell us something new about Earth’s darker culture.
It does provide Amos’ history, coming-of-age in a crime-ridden part of Baltimore. It tells how he managed a crisis and came to get off-world. It doesn’t go back enough to explain his skills or personality.