Sven, our hero, is so tough that he survives being whipped as punishment, and witnesses the slaughter of the garrison he is stationed at. After being held captive by aliens he is rescued by the galaxy's elite special ops force the Death's Head. He joins them and is sent on a special mission.
Don't stop reading if you've read all this before in a million other books. I never said it was original. What it is is a fun read, that won't make you think too hard, and sometimes that's just what the doctor ordered.