Every seat taken, and we sat there in the sudden dark and turned to one another for an explanation, as the rest of the train disappeared into the tunnel.

NEWYORKER: Wakefield

They stood obscured in the sudden woolly dark, next to the fallen motorcycle, which leaked raw-smelling gasoline into the dust underfoot.

NEWYORKER: Nawabdin Electrician

The sudden appearance of dark clouds prompted Rob to yell, "Go, now!"

WSJ: Man Versus the Volcano

One of the injured, Mohammed Ali, said he was standing near a food cart in a crowded area "when all of a sudden it turned dark, dust filled the area".

BBC: Dozens killed by car and suicide bombs in Iraqi cities

If you watch closely, you can see them from the shores of Istanbul: The sudden flash of a dark grey dorsal fin cutting through the water.

NPR: Dolphins Dodge Danger in the Bosphorus Strait

But there was a dark side, well-hidden, and all of a sudden someone opened the door and the dark side came out.

CNN: ASIANOW - TIME Asia

Nowadays, people just jump out of the dark all of a sudden and screech (cheap scare) or creatively disembowel screeching second-string actors (more gross than actually frightening.) Couple that with a veneer of macho stylishness, and you've got yourself a relative facsimile of a motion picture.

CNN: Review: 'John Carpenter's Vampires' stinks worse than garlic

What, then, to make of its sudden removal last week under cover of dark?

ECONOMIST: In the night an old philosopher mysteriously vanishes

It's a huge towering dark cloud, shaped at the top like a blacksmith's anvil, and responsible for sudden downpours.

BBC: Weather talk: Is there a way to make it interesting?