Keepers have invaded Sanctuary and Helen runs down a hallway, tilts back the head of a bust of Shakespeare, and pushes the hidden button to drop the blast doors. The button hidden in a bust of Shakespeare has been an inside joke and favorite of TV shows since it was introduced in the 1960s show 'Batman'.
Will tells the three sisters they have schizoaffective disorder. That condition is innate, chronic, and resembles mild schizophrenia. It presents with hallucinations, delusions and mood disorders. Will thinks the sisters have suppressed their memories in order to avoid dealing with trauma. That would be a dissociative fugue.
Historic, or mythic, hodgepodge. The episode title, Fata Morgana, is an Italian name for a type of mirage and for Morgan le Fey, a character in the Arthurian legends. One witch sister mentions the battle of Badon Hill when Britons fought against the Anglo-Saxons somewhere around 500 AD. The sisters remember the miasma, identified as bubonic plague, which first reached Europe around 1345 AD. The Morrigan is a pagan goddess worshiped widely across western Europe. Magnus found them entombed in Scotland.
Ashley takes Squid a paper bag of mealworms and raw, rolled oatmeal. Mealworms are the most common live food for small pet snakes, lizards, birds, arthropods, even hedgehogs. Rolled oats are the standard food for raising mealworms.
The symbol on the floor between the crypts at the beginning is the same symbol used by Team Razer on their gaming hardware.