Finding Tricky Tactics ERROR

Hi, I am doing the 3rd one, Pillsbury vs. Swiderski and I am at the point where I just moved my dark bishop to attack the queen and it has now retreated. Now I have tried every move and it will not accept one... I think it's unsolvable. Any help?

Cost me three points off my oh so precious entirely imaginary rating in Chess Mentor but no, it's not unsolvable.  Think just a little outside of the box.  What move will increase K safety and bring another attacker into play?

Please tell me the exact moves, because not one will work... lol

I'm not going to go back and look at it again unless I have to, but I think the answer was castle Qside.  If that's not it, let me know and I'll have another go later tonight.

Hey, I let my membership expire, so I'll look tomorrow, but that sounds like a move I may have not tried... Thanks!