Walter, having a lot of time with the Doyles, starts to think that he may have a squatter's claim on being a Doyle. To demonstrate the validity of his claim to the Doyle clan Walter decides that instead of forwarding a juicy case to the Doyles he will do with the investigative work himself, though with some assistance from the masterful Des.
With Des covering surveillance for him while he is in court, Walter soon feels as though he was made to be a PI. The ladies keep coming his way and he can't stop finding clues (even if they are just played out Nevada tickets that aren't really related to the case).
This start to go awry when Jake starts having a hard time keeping Walter on the phone. Jake decides to set up surveillance on Walter to find out what's going on.
Jake's investigation is slowed down by the fact that assigned the actual surveillance duties to Des, who had no interest in letting his boss know that he had been moonlighting and 'borrowing' equipment.
After a few days of disappointing results from Des, Jake decides to have Tinny surveil Des. Soon enough the whole scam falls apart and Walter and Des's ploy is uncovered. Of course, Jake also has to step up and help Walter our as he hadn't really made progress in the investigation (a particularly troubling situation as Walter had opted to be paid in advance).