Skylla

Being between Scylla and Charybdis' is an idiom deriving from Greek mythology. Several other idioms, such as "on the horns of a dilemma" Skylla and Kharybdis were mythical sea monsters noted by Homer; later Greek tradition sited them on opposite sides of the Strait of Messina between Sicily and the Italian mainland. Skylla was rationalized as a rock shoal (described as a six-headed sea monster) on the Italian side of the strait and Kharybdis was a whirlpool off the coast of Sicily. They were regarded as a sea hazard located close enough to each other that they posed an inescapable threat to passing sailors; avoiding Charybdis meant passing too close to Scylla and vice versa. According to Homer, Odysseus was forced to choose which monster to confront while passing through the strait; he opted to pass by Skylla and lose only a few sailors, rather than risk the loss of his entire ship in the whirlpool.