MY MOTHER-IN-LAW is up in the clouds. In my mind's eye, she is somewhere over Tunisia, eating a dry salad, travelling at 530 miles per hour. The stranger sitting next to her has stolen her armrest, her ears are in a state beyond popping and she's having pathological thoughts about the small child kicking the back of her chair. She'll have stared blankly at several films on the tiny screen in front of her and will now be trying to relax into the Whale Sounds channel on the in-flight radio.

Anyone who has made the journey from Tullamarine Airport in Melbourne to Glasgow International will know it's more than a matter of air miles: it is a voyage into spiritual darkness, the kind of burning-legged boredom that makes you want to stab yourself in the face with your plastic fork. To make matters worse, they show you a little electronic map, allowing you to watch yourself creeping over huge swaths of the world's population in brain-curdling slow motion.

The first time you get off to stretch your legs, in Singapore, it feels novel. By the second time, in Dubai, you want to fall onto the tarmac weeping, railing against the size of the world. You want to stamp on your watch because it doesn't make sense any more. How can it be eight in the evening when the sun is just rising? How can it be Thursday morning when you left Australia on Thursday afternoon?

Needless to say, my wife and I are grateful for the effort being made by Nana Reynolds to meet her grandson. Since last week, and especially in the 20 hours she has been airborne, we've been scrubbing and polishing with the energy of people possessed. Small anomalies - none of our doors had handles, the windows were Jackson Pollocked by seagulls - have been corrected. Had we the time, we'd arrange some nice bunting and flags to wave as her cavalcade approaches the flat.

Even for die-hard republicans, it feels like royalty is coming. Some pictures have been taken down from the wall and replaced with others. The postcard of the Queen and Prince Philip in the bathroom has been buffed with Mr Sheen. It has been at head height, for those sitting on the family throne, since we moved in - a cure for or cause of constipation, depending on your politics.

The cat has been groomed, his litter tray disinfected. Our son will be polished last, then pacified with a quarter-pint of breast milk. Because we have taken photos of him in the moments he is tranquil and happy, and not the hours when he is purple and furious, it's hard to avoid worrying that he won't meet his Nana's expectations. Then she might not want to babysit. And where would that leave us? What if she wants to jump on the plane and head straight back to Melbourne? No, that's extremely unlikely.