The deep ocean, read from the record.

Every episode takes one mystery from the deep and asks which specific dive
settled it. Not what might be down there — what the footage, the hydrophone
trace and the dive log will actually support.

The evidence is named on screen: ship, dive number, date, depth, coordinates,
or the paper with its authors. You can go and check it, and disagree with us.

Most of the footage comes from NOAA Ocean Exploration — public-domain video
shot by remotely operated vehicles thousands of metres down, credited on
screen. The diagrams are drawn for each episode from the published numbers.
Where no camera was ever there, we say so, and the reconstruction is drawn,
never photographed.

Some cases are closed. Some are not. When one is still open, we tell you
exactly what is missing to close it.