The Great Gurren Brigade heads moonward in order to protect the Arc-Gurren from the Anti-Spiral attack.  Simon uses his hope in the outcome to power Gurren Lagann and combines with the Arc-Gurren to defeat the Anti-Spirals.  Now all they have to do is stop the moon.  The Lord Genome bio computer reveals his super battle ship hidden inside the moon and Simon attempts to get to the control panel in order to stop the it.  He is confronted by Nia before he can get to it.