The Unthinkable story arc follows the villain Taskmaster as he is put in a precarious situation. If you are unfamiliar with Taskmaster, his main power is to copy physical movements. If Taskmaster witnesses a feat of physical brilliance, fighting finesse, or (I'm guessing here) parkour- he can instantaneously mimic it perfectly. The only problem is that his combat knowledge takes up so much space in his brain that he's had to create a "memory palace" to store memories of non-fighting related things.
Taskmaster's main role in the comic book universe is to run a school for training henchmen. All the Joker's goon's have to go to school somewhere, right? However, the Unthinkable series paints Taskmaster in a new light and puts his past in sharp focus. When he finds himself being investigated by the state for "turning evidence", Taskmaster finds himself with a bounty on his head.
Unthinkable finds Taskmaster struggling against hordes of bounty-driven enemies as he tracks down the leaders of local gangs. If he can track down the gang leaders he can prove his innocence... but it won't be easy.