But now in the shadows
It goes to the bourne
Of Orcus remorseless
Whence none may return.

[Qui nunc it per iter tenebricosum
Illuc unde negant redire quemquam.]

gaius valerius catullus
Catullus (c. 84 BC – c. 54 BC) Latin poet [Gaius Valerius Catullus]
Carmina # 3 “Death of the Sparrow,” ll. 11-12 [tr. Wright (1926), st. 4]
    (Source)

Referring to the fate of his beloved Lesbia's beloved sparrow.

See also Shakepeare, Hamlet, Art 3, ll. 86-88.

Death,
That undiscover'd country, from whose bourn
No traveler returns.

There is no particular evidence that Shakespeare ever read Catullus, but other ancients (e.g., Seneca) quoted these lines from this Carmina. At the same time, post-Shakespearean translators may have been themselves influenced by the Bard's lines in their translations.

(Source (Latin)). Alternate translations:

Poor bird! who now that darksome bourn
Hast pass'd, whence none can e'er return.
[tr. Nott (1795), ll. 13-14]

He now that gloomy path must trace,
Whence Fate permits return to none.
[tr. Lamb (1821), st. 3]

Now he treads that gloomy track,
Whence none ever may come back.
[tr. T. Martin (1861)]

Now to that dreary bourn
Whence none can e'er return,
Poor little sparrow wings his weary flight.
[tr. Cranstoun (1867)]

Now he wendeth along the mirky pathway,
Whence, they tell us, is hopeless all returning.
[tr. Ellis (1871)]

Now he has gone to that dark place,
Whose dismal pathway none retrace.
[tr. Bliss (1872)]

Now must he wander o'er the darkling way
Thither, whence life-return the Fates denay.
[tr. Burton (1893)]

Now it fares along that path of shadows from where nothing may ever return.
[tr. Smithers (1894)]

Now, hs pretty doings o'er,
His little soul goes darkling whither all
Must go, and, going, may return no more.
[tr. Harman (1897)]

Now he goes along the dark road, thither whence they say no one returns.
[tr. Warre Cornish (1904)]

The wee thing’s gane the shadowy road
That’s never traveled back by ony:
[tr. Davies (1912)]

Now he travels the path of shadows, to that place, whence all men agree there is no return.
[tr. Stuttaford (1912)]

Now does it seek the darksome way,
Whence none return nor message bring.
[tr. Stewart (1915), st. 4]

Now he's journeying through the eternal
Darkness, to the relentless shades.
[tr. Symons-Jeune (1923), st. 4]

And now he journeys whence they say
No steps retrace the darkling way.
[tr. MacNaghten (1925)]

Now he is gone; poor creature,
lost in darkness,
to a sad place
from which no one returns.
[tr. Gregory (1931), st. 3]

Who now? It's hard to walk through tenebrous flume
down there, where it is granted not one comes back.
[tr. Zukofsky (1959)]

It now flits off on its way, goes, gloom-laden
down to where -- word is -- there is no returning.
[tr. C. Martin (1979)]

Who now goes through that gloomy journey
from whence they denied anyone returns.
[tr. Sullivan (1997)]

Now he goes down the shadowy road
from which they say no one returns.
[tr. Kline (2001)]

Now he's traveling on that dark-shroud journey whence, they tell us, none of the departed ever returns.
[tr. Green (2005)]

It now goes through the dark journey
to that place from where they deny that anyone returns.
[tr. Wikibooks (2017)]

He who now goes through the shadowy journey
thither, whence they deny that anyone returns.
[tr. Wikisource (2018)]