Lt. Derek Vega is an aging police officer who once helped a young Ace get out of Blackjack's grasp.  Since then, they have bacome good friends, and now Vega often relys on Ace and Cosmo to help him on tough cases.  Of course, Vega also has to put up with his share of frustrations, mainly his Captain, Freidricks, who always thinks he's right, and never really knows what he's doing.