Prince of Persia: Warrior Within Hints for PC
For An alternate ending you must collect all nine life upgrades to do this take a look at the walk throughs page to tell you were to find them.
If you find them then you will continue the game until the next time you go to the hourglass room where youll find a new sword called the water sword, the only thing that will affect the Dahaka.
When you go to fight the emperass again you will fight the dahaka instead (to beat him fast use ravages of time)
P.S. The 5th upgrade pedestal is in the second garden not the first.