Based on the context and the answer, generate a question. 

Context: I ' m doing this job as one , one last job for someone I once knew . For old time 's sake . I used to do jobs like this all the time ; I used to relish the dark . I used to be a PI , a man who could find things out on the quiet .

Answer:

They are getting old .



What may be the reason for them not doing PI work anymore ?