Detective and his City

He was one of the boldest detectives in town so he had been willing to take on the job. It would be the last one before his retirement. At least that was the plan. After tracking every lead and covering all of his bases he realized they had left months ago, and gone across the river into the City proper. His contacts there were all long gone. He was sure of himself but standing at the riverbank he didn't know if he would be able to track them down.