In the gym, Catburglar is making a sweat for his next match. That will give him advance. But the interesting part is the crowbar he is not giving you.
This is the low-spoiler guide for "Getting the crowbar" puzzle in The Darkside Detective - A Fumble in the Dark. Unlike in normal walkthrough, you get gradual hints on how to solve the puzzle. Click the big button below to see your first hint. If the hint contains a spoiler, you will be warned about it before clicking.