My brother is working on a new fuel for his rocket car.  He's brilliant, he really is.  So brilliant that... I think that new fuel he's designing is strong enough to eat right through the car's chassis!$B$BI want to reinforce its fuel tanks before that happens.$B$BThe tortoises out on the flats have very hard shells.  I want to use them to create new tanks for our rocket car.  Tanks that can hold my brother's new fuel.$B$BYou look responsible enough.  Will you get me those shells?