Imagine all of the homework that these Marvel (or any company for that matter) storytellers have to do to really get to know the history of the superhero or villain that they've taken on in a story. For instance, take Wilson Fisk, or the Kingpin, as an example. He has evaded hard time even though he was a mob boss that was involved in numerous criminal activities. Just ask Daredevil! He is currently the Mayor of the very same city that he controlled as a gangster. Then again, maybe he is still that person. Understanding Fisk's character is something that writers Jackson Lansing and Collin Kelly do very well, as witnessed in Devil's Reign: Winter Soldier #1. Equally up to the task are artists Nico Leon and Felipe Sobreiro.
During Fisk's war on vigilantes, he has created files on many of these crime fighting good/bad guys. But what happens if a file contains information that even the hero doesn't know exist? Such is the case with James "Bucky Barnes. He has seen glimpses of his past through dreams. However, sleep doesn't come easy for Bucky. Peers that knew him back when have died. But Fisk may have info on him in his files at Gracie Mansion. He realizes he must break into the Mayor's home to find out.
This appears to be a weird evening for a break-in, as Fisk is preparing for another kind of nightmare. He ensures that his wife isn't home. Also, the guards on duty are only those without loved ones. The tossing and turning that Fisk does at night leads him to sleepwalk. Bucky enters with no problem and finds a trail of dead bodies. He retrieves his file. Then, he encounters a sleepwalking Fisk with blood on him. A struggle ensues and it takes awhile for Bucky to realize that Fisk is sleeping. The stairs begin to collapse as well as the ceiling. Bucky's only thoughts come from his training: "Complete the Mission." He does and gets the hell out of there. Falling into the rubble brings Fisk out of his sleep only remembering a beautiful dream. However, Bucky's nightmares are about to begin as the file he holds in his hands were stolen by Fisk from somebody very powerful. Powerful enough to want to protect Bucky's secret violent past.