The group is gathered together by Mr. Johnson. The group has a specified goal, like blackmailing a mob boss, or performing a dangerous extraction. The characters are promised support, if needed. They go on the job and encounter heavy resistance. The support that was promised never shows up, the characters are hung out to dry. It would seem that the job was just a distraction that the Corp's solos could perform a job easily, seeing that everybody was hunting the PC's.
The PC's have a reason to hate the Corp that hung them out to dry, and need to look out for the ones that they crossed. Could even have cops, or CIA looking for them because of the first run. Makes for an interesting, if short, life.