Looking for BBC fic

[piplover.livejournal.com]

Hi!  I'm looking for a BBC fic where Sherlock dressed up as a woman to lure out a killer who murdered abusive husbands.  Sherlock used a transgender consultant to help him get his mannerisms right and John played the abusive husband. They went to a party where Sherlock played bait. 

Any help would be appreciated. Thanks!