This episode title comes from the expression "caught between a rock and a hard place" which refers to two mythical beasts in Greek mythology. Scylla was a monstrous multi-headed spider who would eat hapless sailors passing near her cave. However, in order to steer clear of this catastrophe one would have to sail near Charybdis who was supposedly able to swallow a large portion of the ocean (including ships) and spit it back out (without the ships, of course). The same expression was also a popular phrase used during the 1920's in America. The rock in this Lizzie episode refers to the stone Matt tries to grab from David Carradine in his movie, and the bra part obviously refers to Lizzie's first shopping trip for one.