Justin Hammer was put in the Seagate Prison during the events of Iron Man 2.
Justin Hammer saw that The Mandarin was put in the cell before him. They started working together. Later Carl Creel, a criminal also joins them. They all want to kill Tony Stark. During a fight, The Mandarin killed the other prisoner called Eric.
Justin Hammer and Carl Creel were waiting for what The Mandarin would do. Later they heard that he was killed and they were both very angry.
To be added