Darkness

[FrankFrank]

There is a depth so dark within
where oft we fear to walk
a bitterness and barrenness
that tears our very soul

[Billy]

I'm a little confused. When I read "depth", I think of something good, but this depth is dark and we fear to walk there.
This would make it a tanka:

a dark
we fear to tread
a bitterness
and barrenness
tears our soul

[FrankFrank]

No, nor really a tanka, just a very ordinary thought.