I was reading some of the user reviews for Deadlock and someone mentioned that the "secret" Deadlock song wasn't included with the gog release and linked to it on youtube. It was kind of an easter egg that was just included on the CD. It was composed by Paul Kwinn who was one of the senior programmers for Deadlock.

If i ever get back home again that recruiter's gonna die...

Search the internet for DEADSONG.WAV for the original, or just DEADSONG for converted files.
If you don't care to have the actual file, it's on YouTube.

The install folder contains the "deadsong.wav". I was surprised to see that it wasn't included in the extras. It is included in the install folder though.

Really nice to know. I really like that song.