For starters, congrats on being 6 mos cigarette-free. No matter how stressful, this is no time to light up. Do whatever it takes to resist the urge - chew the gum; wear the patch; get plenty of exercise; etc.
Always remember, there's nothing more addictive than cigarettes. It's the only thing on the market that, when used as directed, will kill you. Your son doesn't need that. Your job, right now, is to do the right thing.
Rule of thumb = Doing the right thing will always cost you something.
Now then. Down to the business at hand. First thing Monday AM:
1) Go to ex parte at your local courthouse (in Illinois) and get a Writ of Habeaus Corpus. You'll need to draw up an affidavit, produce evidence and/or witnesses.
For you, this is Job #1. This instructs police in your state to do whatever it takes to locate your son and return him you. You, in turn, must bring him to court as soon as he's in your custody.
Bottom line = Do whatever it takes to get that writ!!
As of this moment, you are a man with purpose. Let no one or no thing dissuade you from that purpose.
Translation = Do not pass Go. Do not collect $200.
2) Take that writ to ex parte in courts of competitent jurisdiction in each of those other 2 states (Missouri & Iowa) and get "Writs of Assistance." These writs instruct local police in those states do do the same as paragraph #1, namely help you locate your son and return him to you.
I trust we are clear on this!!
3) Be ready for all hell to break loose.
4) Once you have your son, go back to ex parte and get temporary custody, supervised < parenting time > for your ex, and all that other stuff outlined in The List. Leave nothing to chance.
Remember, what's done in ex parte is only temporary
5) Go back to Family Court and file a Motion to Shorten Time. You've got good cause. Also file charges against your ex for custodial interferrence. Do the same in criminal court for her parents. That'll keep the other side busy and, at the same time, buy you the necessary time you'll need to take care of business.
Your moment has arrived. It's up to you to make your move and make it count.
The idea is to keep the other side busy where they have to play catch-up. Hopefully, they'll never catch up.
Show no mercy. Take no prisoners.
Lock & load.
Everyone is entitled to my opinion. - Maxine™