I'm sitting in my office working on a paper I'm writing with Moritz and Thomas.

The foreign cicadas outside my window are making a damn racket, "It's hot! It's hot!" they ululate in unison. Not with the glee that the Korean cicada's have when they ululate about the heat, or with the defeat that lines my tone when I talk to my co-workers about it, but with a sombre, almost religious, ululation. Maybe smug even. Definitely smug.

(There are two main kinds of cicada in Korea. Their designation as 'Korean' and 'foreign' seems to be one of my wife's invention.)

The ululation has broken my concentration. "Ululate this!" I think to the smug insects. Then realising what they are ululating in their insectial chorus, I must concede it: "It's too damned hot."

It is hot. I wonder why I have not put the air conditioning on yet. Probably should have done that when I got into my office.

I look down and see that someone has sweated all over the front of my shirt. I look about, my fingers curled over the ready position of my keyboard, but the only person in my office, sweating or otherwise, is me.

This is what math is like, at its best. You get involved in a problem and become completely unaware of what is going on around you. How did someone get into my office, sweat all over my clothes, and then get out without me knowing about it?

And why didn't they just use a towel instead of my shirt.

I go look in the hall for some inconsiderate student sweating all over the place, but it is empty. I put the sign on my door to 'Out of office', then going in, close and lock the door.

I put the air conditioning on, and get back to the paper.

Minutes later, my wife calls, and asks when I'm coming home.

Damn, I think, not believing I've worked right through the day and missed lunch again. Looking at the clock, I see it is only 9:30am.

"It's only 9:30, I say."

The cicadas answer me, reminding me that it is hot, but my wife says nothing.

"But it is Saturday," I realise, "I'll be right home."