Acquainted with the Night
From Tardis Wiki, the free Doctor Who reference
"Acquainted with the Night" was a poem recited by Esther Drummond to Gwen Cooper. Its verses included:
I have been one acquainted with the night. I have walked out in rain and back in rain.
Esther noted that the poem was most likely not about walking, but about death. She later rethought, and figured that, as it was written by Robert Frost, it could very well have simply been about walking. (TV: Dead of Night)