Billy's reinstatement at the SIU was initially greeted with considerable muted animosity. Everyone felt that he was a crook and no one wanted to talk to him. His slightly sinister off-putting appearance and innate belligerence didn't help. However, to the rookie cops he was a figure of interest, and anyway Dignam said Billy was a cop, so Billy must be a cop. Once Billy's story got round, the other cops stopped giving him the cold shoulder, although they continued to avoid him. At least Billy would now get invited to the yearly social do's.
This worried Sullivan. There was now no way he could drive a wedge between Billy and the other cops, and it would be dangerous to undermine either Billy or Dignum openly. Best to stay clear of them and keep his nose clean.
But it had upset Billy. So a few days later found Billy in the restaurant near to Maddy's clinic, fingering his badge. Maddy recognised it as a displacement activity indicating insecurity. She made her decision.
Holding Billy's hands she said "I'm pregnant".
"Does he know" asked Billy in a neutral tone which masked his true feelings.
"Yes. And I'm going to call the baby William", she replied.
Billy was unsettled and off balance, "Why that name".
"Because that's his fathers name", she replied quietly.
Maddy paused then said "His fathers name, your name, not his foster fathers name".
Billy was paralysed by this revelation.
Maddy continued, "Well, you always said that I was a liar, so there should be no problem with little Billy having two fathers."
That really made Billy incapable of saying anything.
Then Maddy said in a determined manner, "So, you are going to go to your current psychiatrist, tell them about your change of circumstances and ask to be transferred back to me. Then everything will be above board and ethical".
Billy wasn't so sure of either the above board or ethical, but he did as he was told.
Not that it would matter. Three months later Billy, working undercover, finally tracked down Costello's lawyer who was forced to divulge a host of interesting documents. Sullivan escaped Billy's police squad by a mere five minutes, but only because he knew of a hidden access into the apartment block's crawl space. Barrigan also tried to hide but his lack of real ability soon lead to Billy's hand on the back of his neck.