Question: After Nick and Carver's confrontation in the restaurant, as Cassie and Nick arrive back at the new hotel, we see Hook Waters, along with Pinky, standing in the waiting room. Why was he there and how did he know where they were? (01:05:00)
Question: At the end of the movie we find out that it was really soy sauce that was injected into Nick's arm. Wouldn't injecting soy sauce directly into your blood stream still kill you, or at least have some sort of ill side effects?
Answer: Soy sauce is mostly soy protein and salt in water- it might raise your blood pressure for a while, but assuming you're in reasonably good health, and presuming it wasn't a ridiculously large amount, your liver will filter it out after a short while.
This is incorrect, there are several variables in this but given the syringe size I'm guessing that he injected approx 50ml. Now 50ml injected intravenously would almost certainly cause sepsis and he would die from septic shock within a day or so. The reason for this is that soy sauce is a fermented product full of several different types of bacteria in large quantities which would be quite friendly in the gut but disastrous in the blood stream. Also the sodium and yeasts and funghi in the sauce would not be good either. If however the injection was subcutaneous but not intravenous then it may not be fatal but it would certainly give him a very nasty infected cyst that would have the potential to be fatal if not treated correctly.