When Leslie and Ann volunteer for Kaboom! they help the non-profit put up a park in a single day.  Suddenly, Leslie questions her entire bureaucratic career and decides to go rogue and fill in the pit behind Ann's home on her own terms.  Leslie, with Ann's help, hires a back-hoe and as they start to fill in the pit they realize Andy is still living their, despite him lying to Ann otherwise. 

Andy ends up in the hospital and he attempts to sue Pawnee and isn't answering nay of Leslie's calls.  She goes to Ann for help and Andy instantly answers her first call.  He agrees to meet at her house and shows up naked.  After putting on some clothes, Andy and Leslie hatch a plan and the next day Andy settles with the lawyer for one condition... the pit is filled in.  Ann sees his generousity as the pit is being filled in and even gives him a little wave.

At the end of the episode, the organizer of Kaboom! drives away on his boat claiming to have made up the organization as a prank.  The organization, however, does exist in real life.  Look it up.