A loose tentative translation of mine:
What was was.
If there´s something that remains
It´s the bitter marks
Etched in the dark surroundings.
If what was could be back
It would bring with it a fatal error
As it would lack the quality of being real.
(or simply "as it would not be based on reality")
Now, therefore, the past is in the past.
If it comes back, it´s not life, it certainly means death.
So, why then my heart is beating faster?/is skipping a beat?
If something (from the past) comes back, it has to be death/it has to do with death.
Coming from a learner, so it may or may not be good, so it´s only for informational use. Let´s wait for further comments, insights and improvements.