His preoccupation with computers-- his detailed, seemingly foolproof plan-- his knowledge of scientific programming-- his complex, yet brilliantly executed moves-- It all adds up to one diabolically dangerous figure... The Mad Thinker!! 
Appearing in "By Ben Betrayed!"
Featured Characters:
Supporting Characters:
Antagonists:
Other Characters:
- New York Fire Department
- ⏴ Dr. Jose Santini ⏵
- NYPD
- National Guard
Races and Species:
Locations:
- United States of America
- New York City, New York State
- Manhattan
- Baxter Building
- Murray Hill (First appearance)
- Manhattan
- New York City, New York State
Items:
Synopsis for "By Ben Betrayed!"
With Ben turned evil he goes on a rampage through New York City with his comrades trailing behind him trying their best to stop him, leaving the bogus Dr. Santini -- dropping his disguise to reveal that he is really the Mad Thinker -- with full access to Reed's laboratory. The Thinker boasts that once the Fantastic Four have been defeated, he will no longer be known as the Mad Thinker, but instead will be recognized as the All-Powerful Thinker.
While the FF and the National Guard try to stop Ben's rampage across the city, the real Dr. Santini awakens to find that he's being watched by a powerful Android, and the Mad Thinker finds Reed's portal to the Negative Zone. Before the Thinker can decide what to do with the portal, he reasons that if Reed Richards is still alive then Reed will figure out soon who was impersonating Dr. Santini, and thus he rushes back to his hideout to deal with the real Dr. Santini before the police arrive. Just then, taking a break from fighting the Thing, Mr. Fantastic comes to the realization that this series of incidents could only have been orchestrated by the Mad Thinker and asks the police to help in sweeping the city to try and find the Thinker's hideout.
While elsewhere in the city, the rampaging Thing manages to slip past the authorities, dead set on ruining Reed Richards once and for all.
Trivia
- There is one moment in this issue in which the Thing is scaling up the side of a skyscraper while small planes fire at him. This scene seems to be inspired by the famous climax of King Kong.