I determined the Visual Flight Rules page must be what he was looking for since Soth hasn't had a lot of alone time lately. On Thursday, I was sitting on the couch drinking my coffee when I noticed that Soth went to his downstairs litter box, scratched around, got out and then went upstairs and repeated those actions. Then he came back downstairs, squatted in front of the window and only a tiny dribble came out on the carpet. Immediately, I ran to the litter boxes that had just been scooped and there was nothing in either one and I panicked. With Soth's FLUTD, a blockage can happen easily and that can be fatal.
Since Soth was able to get a little dribble out, I knew he wasn't blocked, but I was worried he could be soon. He was definitely straining to urinate and I knew he was in pain. I followed him around every time he went to one of his litter boxes to see if he'd been able to go. The girls followed him around wherever he went, too.
Our vet is closed on Thursdays, so I sat and stared at Soth and willed him to tell me if he needed me to take him to the ER vet. Thankfully, we had one dose of pain medicine left from the last time we had this struggle and after I tackled him and got the pain meds in his system, he was able to urinate more normally and we could wait to call our vet on Friday morning. Right now, he's on more pain medicine to give him a chance to flush out his bladder on his own and if this continues, we'll do more x-rays to see if there are big crystals irritating his bladder.
According to the Wikipedia page Soth found, Visual Flight Rules are the rules governing visibility for pilots with things like cloud distance to be able to control a plane's altitude and avoid obstacles. I think Soth must have been feeling smothered, so he has decided to fly away.
He's going to be so disappointed when I tell him that they don't let you fly aircraft when you're taking pain medication.