The moment: The X-Men are in serious trouble when the Alkali Lake dam bursts and the X-Jet malfunctions, leaving them powerless to the torrents of water that threaten to flood the aircraft. Making the ultimate sacrifice, Jean stands in the midst of the chaos; one arm holding back the rising tide, the other lifting the X-Jet out of harm's way. At the last second she finally stops, letting the water engulf her.
Mutant magic: Jean struggled for so long to control her powers, and finally, her crowning achievement in harnessing them results in her sad, tragic demise. *sniff* Bit dusty in here, isn't it?