The Wild Wild West (1965)

S3E4 The Night Dr. Loveless Died

The agents head to Hayes City to confirm the identity of their longtime foe, Dr. Loveless. During their visit, they encounter Dr. Liebknicht, a Swiss neurologist and Loveless's relative. As they investigate a crucial key discovered with the body, they soon uncover that Loveless is very much alive and has sinister intentions of using his medical expertise to perform a lobotomy on Jim!