After snapp​ing another photo as quickly as my camera could recover, it appears whatever I caught at the end of the corridor was gone.  The other investigator and myself quickly went to the end of the corridor, and we found absolutely no trace of another human.  I am not claiming this is an image of a figure, it could very well be a shadow effect.  It is very intriguing, and after several investigators experienced random objects ( nuts and screws) being tossed in our general direction, it makes me wonder if the renovations stirred things up?.