The character Castus is introduced here as one of the Cilician pirates. According to history, the real life Castus was a Gaul and one of the rebel leaders serving alongside Spartacus with Crixus and Gannicus. His role as a leader is shadowed by the character Agron while the on screen Castus stands at odds with Agron because of their shared affection for Nasir.
After Heracleo informs Spartacus of his deal with the Aedile, he proposes drinks, which Spartacus turns down and tells Heracleo to return to the city after sunset. Heracleo agrees by saying, "as you command, King Spartacus." Though Heracleo was being sarcastic, his remark is somewhat ironic seeing as the Romans named the Gladiator after the Thracian King Spartacus of legend.