I Only Have Eyes For You

In which there are dead people at the High School. Not the freshly killed kind like normal: ghosts.

From the old WB Buffy website:

LOVE IS FOREVER -- Buffy encounters a tortured spirit haunting the halls of Sunnydale High and recruits her friends to help the bitter spirit in its quest for peace. Meanwhile, Giles is filled with anguish when he believes the spiritual being is Jenny trapped and trying to impart a final message to him from the beyond.

Cross-reference:

episodes named after songs:

• Bewitched, Bothered And Bewildered
  Rodgers and Hart, from the musical "Pal Joey"
• Lover's Walk
  Elvis Costello
• This Year's Girl
  Elvis Costello
• Who Are You?
  The Who
• I Was Made To Love You
  Stevie Wonder
• Hells Bells
  AC/DC
• Help
  The Beatles
• Bring On The Night
  Sting
• this episode
  The Flamingos

Cast:

• Sarah Michelle Gellar as Buffy
• Alyson Hannigan as Willow
• Nicholas Brendon as Xander
  

  ---

• Anthony Stewart Head as Giles
• Charisma Carpenter as Cordelia
• David Boreanaz as Angel / Angelus
• Armin Shimerman as Principal Snyder
• James Marsters as Spike
• Juliet Landau as Drusilla
• Brian Reddy as Bob
• James Lurie as Mr Miller
• Meredith Salinger as Grace Newman
• Christopher Gorham as James Stanley
• John Hawkes as George
• Miriam Flynn as Ms Frank
• Brian Poth as Fighting Boy
• Sarah Bibb as Fighting Girl
• Ryan Taszreak as Ben
• Anna Coman-Hidy as Fifties Girl #1
• Vanessa Bodnar as Fifties Girl #2