Who Are You?

In which we discover that identical cousins aren't the only people that can switch identities, Willow doesn't drive stick anymore, Joyce has balls, and the Watcher's Council can't hang on to their girl.

Official back-of-box synopsis:

Buffy battles to escape the clutches of the Watcher's Council special operations team who plan to send her to England, while Faith continues to wreak havoc in the lives of Buffy's family and friends.

From the old WB Buffy website:

THE CONCLUSION OF A TWO-PART EPISODE WHEN FAITH RETURNS - Buffy battles to escape the clutches of the Watcher's Council special operations team who plan to send her to England, while Faith continues to wreak havoc in the lives of Buffy's family and friends. Meanwhile, it's Willow and Tara who figure out Buffy's whereabouts, but not before Faith has done some serious damage to Buffy's relationship with Riley.

Links:

This episode's page at http://www.restlessbtvs.com/, the Restless BTVS Trivia Guide

This episode's page at http://www.vrya.net/bdb/, the Buffyverse Dialog Database

Cross-reference:

episodes featuring the watchers' council:

• Helpless
  They give Buffy a vampire serial killer for her birthday
• Checkpoint
  Glory's a god, so what? Where's Gile's back-pay?
• Never Leave Me
  The council falls victim to a particularly cheap-looking explosion
• this episode
  They imprison Faith, only it's Buffy, so it's lucky they suck at imprisonment

episodes in which there's dancing:

• When She Was Bad
  Bad!Buffy has Xander all hot and bothered
• Faith, Hope And Trick
  Faith is first seen dancing
• Bad Girls
  Buffy and Faith dance subtextily together
• The Prom
  Buffy and Angel 4 EVA!!!
• The Replacement
  The Snoopy Dance
• Once More, With Feeling
  Again with the "well duh!"
• Him
  Daddy like! Oh my god that's Dawn!
• this episode
  Faith takes Buffy's body onto the dancefloor

episodes named after songs:

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

episodes with major moments in Willow and Tara's relationship:

• Hush
  Willow and Tara meet
• The Yoko Factor
  Willow says for the first time that Tara's her girlfriend - "bloody hell!"
• The Body
  their first public kiss
• Once More, With Feeling
  Tara realises Willow's using magic to influence her
• Seeing Red
  losing Tara, Willow will never be the same again
• this episode
  "I am, you know" - Willow and Tara get together for the first time

episodes with subtle callouts to previous episodes:

• Phases
  Oz notices a cheerleading trophy's eyes "seem to follow you"
• Buffy vs. Dracula
  Xander is sick of being the guy who gets the "funny syphilis"
• Gone
  Xander asks Invisible-Buffy if she's been "feeling ignored lately"
• Chosen
  The earth is "definitely doomed" according to Giles
• this episode
  Willow asks if Tara sensed any "hyena energy"

Cast:

• Sarah Michelle Gellar as Buffy
• Sarah Michelle Gellar as Faith in Buffy's body
• Alyson Hannigan as Willow
• Nicholas Brendon as Xander
  

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• Anthony Stewart Head as Giles
• Kristine Sutherland as Joyce
• James Marsters as Spike
• Eliza Dushku as Buffy in Faith's Body
• Emma Caulfield as Anya
• Amy Powell as TV News Reporter
• Marc Blucas as Riley
• Leonard Roberts as Forrest
• Amber Benson as Tara
• George Hertzberg as Adam
• Chet Grissom as Detective
• Alastair Duncan as Collins
• Jeff Ricketts as Weatherby
• Kevin Owers as Smith
• Rick Stear as Booke
• Rick Scarry as Sergeant
• Jennifer S Albright as Date