The adventure gives the option of starting the players in different locations but I thought that would really slow things down so I had Daredevil (as Matt Murdock) show up to speak to his client, the Sentry, with Luke Cage as a body guard. Captain America was there on a tip that something was going to go down and Iron Man was installing a new cell for a super criminal he had just captured.
When the heroes were assembled... boom! An explosion rocks the facility and the power goes down! The heroes are stuck in the lower levels in the dark with dozens of escaping criminals! Count Nefaria is the first to encounter the heroes and they put him down quickly! Murdock decides to go see his client, the Sentry! Seeing Nefaria go down, the Living Laser, Armadillo, and Tiger Shark all jump on the heroes. In a prolonged battle the heroes stood victorious!
The heroes follow the sound of the gathering mob! When they round a corner they see dozens of escaped supervillains all trying to make their exits! Captain America tells the mob to stand down and return to their cells. The answer is laughter... followed by "Get them!" The mob quickly swarms the heroes. Cage is picking up people and slamming them down, Cap is flinging his shield all over, and Iron Man is releasing his Uni-Beam! Finally, the mob is subdued!
It's then that the heroes here BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM - eight booms seemingly starting on this level but heading away. When they get to the source of the sound, they see a hole opened in the ceiling of the Sentry's cell which goes all the way to the outside. It seems that Murdock was successful in persuading him to rejoin society... The heroes have Iron Man give them a lift up through the hole. When they get to the surface they see scores of SHIELD agents swarming the prison from boat and helicopter.
Iron Man gets the backup generators online. Cage interrogates the Grey Gargoyle to find out that Electro was behind the attack to free Sauron and that they're on their way to the Savage Land. The heroes, of course, pursue...