Task: Question Answering
Input (English): Mohinder gasped softly as he watched the serum disappear from the tube and into his veins . It felt strange for a few moments after ... tingly . Mohinder wondered how he'd test it , then he thought that he could at least take a sample of his own blood to see if anything had changed within . Quickly , he rushed back inside but in his excitement to see the results of his experiment -- he tripped and his body started to head straight for the tall glass window . 
Question: What may have caused Mohinder to trip ?
Output (English): The strange substance intoxicated him .