Any 4-letter word

 I  - - - -  you;

The space between, 

Both liminal and concrete, 

Exists. 

During a piano concerto 

On the mezzanine

We embraced, for a while,

Before and during and after

Then time resumed

And Bernard, for once, 

Never even knew 

How close he had been  

To something good, and infinite, and true.