What was it? (Spoiler)

Yep! I thought it was a mix of 'Creep' but with a slight vibe of 'The Descent'. I'm extremely uncomfortable with such violent rape scenes in movies anyway but this was really nasty. I kept watching because it promised 'horror' and it could have been a good horror film without all the nasty in the first half. What was in the oddly large injection anyway? ! It kinda looked like blood or even some sort of paint but I couldn't tell. Plus why would these men have it? Oh well, just another shake camera until viewers get headache movie.