I forgot what was the plot have to reread again

It's a bit blurry. But mainly the ML needed the MC to find a USB that his dad was hiding for ML grandfather, which basically proves that he had his mother killed and ect. I'm not sure what's really going on now because he has the USB now. I guess the ML is in the process of building a case against his grandfather. Not sure what's going with the MC since the dirt bag loan shark is gone and his debt has been paid.