In Simple Genius Sean and Michelle are having serious relationship problems. In spite of all that Sean can do Michelle seems to be in a downward spiral. Michelle has gone into a local bar, picked on the biggest and meanest man in the bar and then despite her training allowed herself to be beaten unmercifully. She makes little effort to defend herself and ends up unconscious.

After Sean witnesses the aftermath of Michelle's apparent death wish, he is convinced Michelle needs serious help. Help he is not qualified to provide, so he convinces her to sign herself into a psychiatric hospital. Michelle discovers that she has childhood issues that are causing her death wish, while Sean is left to investigate alone the suicide of a scientist found on the grounds of Camp Perry, a rather secretive CIA establishment.

As the trail seems to lead to a secret group of scientists and geniuses who are determined to build the most sophisticated microprocessor in the world, Sean realizes that he needs the help only Michelle can provide for him.

Rather than let Sean carry on alone, Michelle signs herself out and lends her brains to the puzzle at hand. Strange though it seems all trails seem to lead back to the hospital where Michelle was staying.

Can the couple solve the mystery before all hell breaks loose and destroys not only them but perhaps the whole world? This was a great book and another jewel in the crown of David Baldacci.