Answer:
this phrase means that all the evil steps and measures taken went in vain with the discovery of the dead body
The origin of idiom "Take a rain check?" is that you will try to do that thing later. Meaning you take a rain check and use it later instead, that is what the idiom "Take a rain check?" means.
It is a fragment.
Although it has a subject and predicate, it is a subordinate clause as it starts with 'especially', indicating an adjective or adverb clause.