Writers: Bill Prady
Aired: 03/17/91
Code: 518
Rating: 8.6 (based on 73 votes)

Al is haunted by a tune heard on the radio which he can hum but not name. He similarly haunts Kelly's date who learns that he can look but not touch. [Note: this episode features the first appearance of the "Top of the Heap" characters. Also, the ending credits have Al's mystery song playing: "Anna (Go To Him)" by Arthur Alexander, instead of the regular theme music. Charlie sings a variation of the Patty Duke Show theme song.]