While performing a geological survey, Riker contracts a mysterious disease that attacks his central nervous system. Dr. Pulaski tries to save him with a potentially lethal course of treatment.

Diana Muldaur (Dr. Katherine Pulaski)
Colm Meaney (Chief Miles O'Brien)

• "Riker's Greatest Hits." Widely regarded as one of the worst Next Generation episodes, where Dr. Pulaski probes Riker's brain to trigger memories which cause emotional responses which attack the disease (i.e., it's a flashback episode).
  
• This is the last appearance of Dr. Pulaski.