Hartwell Brokerage.
First Appearance: "Fool for Love."
Details: The workplace of Jack Mitchell, Hartwell Brokerage was located on the corner of 6th and Mason. After Jack's date, feline feral Donna Morse turned up missing, Brennan Mulwray and Jesse Kilmartin found out that Jack Mitchell was the last to see her alive, and paid a visit to his place of business to question him about Donna's whereabouts.
Trivia: ~ In "Fool for Love," the name of Jack Mitchell's office is Hartwell Brokerage, located on Mason street. J Mason Hartwell was a short-lived character in the DC comic book New Gods #10: "Earth -- The Doomed Dominion."