第５話−１５ ヘリウムボイス(Episode５−１５ Helium Voice）

They say that their voice is strange.

This is Helium Voice.
In the deep see the compressed air causes anesthetic.

Moreover, breathing becomes painful by compressed air.
So they need to supply a gas mixture of helium and oxygen.
Then the voice becomes abnormally high．

It is pitch black outside the window．
They're screaming that they entered to the black hole.

The ship is full of screaming like a duck.

HUFF