Penny Dreadful, Season 3

Dorian:
Do you not yet comprehend the wicked secret of the immortal? All age and die, save you. All rot and fall to dust, save you. Any child you bear becomes a crone and perishes before your eyes. Any lover withers and shrinks into incontinence and bent, toothless senility, while you, only you, never age, never die, never fade - alone. But after a time you'll lose the desire for passion entirely, for connection with anyone, like a muscle that atrophies from lack of use. [glances at the portraits] And one day you will realize that you have become like them - beautiful and dead. You have become a perfect portrait of yourself.

Lily:
An eternity without passion, without affection, caring for nobody...

Dorian:
[smiles] A small price to pay for such immortal perfection, don't you think?

Lily:
Goodbye, Dorian. I hope they watch over you.

[she leaves]

Dorian:
You'll be back, and I'll be here. [pause] I'll always be here.