H2O: Just Add Water - Season 2 Episode 21 : And Then There Were Four
H2O: Just Add Water revolves around three teenage girls facing everyday teen problems with an added twist: they cope with the burden of growing a giant fin and transforming into mermaids whenever they come in contact with water.
First Air Date : Jul 07, 2006
Last Air Date : Apr 16, 2010
Runtime : 24 min.
Genre : Drama, Family, Sci-Fi & Fantasy
Stars : Phoebe Tonkin, Cariba Heine, Indiana Evans, Luke Mitchell, Burgess Abernethy
Quality : 
- Eps. 1 : Stormy Weather2007-09-28
- Eps. 2 : Control2007-10-05
- Eps. 3 : The One That Got Away2007-10-12
- Eps. 4 : Fire and Ice2007-10-19
- Eps. 5 : Hocus Pocus2007-10-26
- Eps. 6 : Pressure Cooker2007-11-02
- Eps. 7 : In Hot Water2007-11-09
- Eps. 8 : Wrong Side of the Tracks2007-11-16
- Eps. 9 : Riding for a Fall2007-11-23
- Eps. 10 : Missed the Boat2007-11-30
- Eps. 11 : In Over Our Heads2007-12-07
- Eps. 12 : Fish Fever2007-12-14
- Eps. 13 : Moonwalker2007-12-21
- Eps. 14 : Get Off My Tail2007-12-28
- Eps. 15 : Irresistable2008-01-04
- Eps. 16 : Double Trouble2008-01-11
- Eps. 17 : Moonstruck2008-01-18
- Eps. 18 : The Heat Is On2008-01-25
- Eps. 19 : The Gracie Code (1)2008-02-01
- Eps. 20 : The Gracie Code (2)2008-02-08
- Eps. 21 : And Then There Were Four2008-02-15
- Eps. 23 : Reckless2008-02-29
- Eps. 24 : Three's Company2008-03-07
- Eps. 25 : Sea Change2008-03-14
- Eps. 26 : Unfathomable2008-03-21
