phantasmagoria

A popular 18th- and 19th-century form of theater entertainment whereby ghostly apparitions are formed.

A series of events involving rapid changes in light intensity and color.

A dreamlike state where real and imagined elements are blurred together.

this mental phantasmagoria

1874, Marcus Clarke, For the Term of His Natural Life Chapter V It is impossible to convey, in words, any idea of the hideous phantasmagoria of shifting limbs and faces which moved through the evil-smelling twilight of this terrible prison-house. Callot might have drawn it, Dante might have suggested it, but a minute attempt to describe its horrors would but disgust. There are depths in humanity which one cannot explore, as there are mephitic caverns into which one dare not penetrate.