O Progeny of Heav’n, Empyreal Thrones,
With reason hath deep silence and demur
Seiz’d us, though undismay’d: long is the way
And hard, that out of Hell leads up to Light;
Our prison strong, this huge convex of Fire,
Outrageous to devour, immures us round
Ninefold and gates of burning Adamant
Barred over us prohibit all egress.
— BOOK II John Milton Paradise Lost.