On my way back to Omdurman I get a call from a senior student Tawfig. Evidently a gang of 4th years have gone for a picnic on the Nile and maybe I would like to join them?

In fact I'd rather go home, change, eat, and re-hydrate first - so I promise to find them later. When I finally arrive Tawfig has already gone – so has any food, but there are about 12 students including Mango Juice Girl. She's wearing an olive green "Pakistani" (a 3/4 length jacket over matching trousers), a headscarf tied around the back of her head (revealing cheeks, ears, and neck) and no shoes. In the conservative world of Sudan this is her swimming costume. We're pleased to see each other and immediately go for a swim in the river. It's lovely to cool off, but actually the wind has a bit of a nip to it and soon it is actually cold sitting around in the water. We get out and drip dry. I talk nonsense and complain that there's no food left. Of course there's no sympathy, I could have come earlier or brought my own.

Just then I am aware that two other girls are standing in the river chatting-up some boatmen. We are opposite an island I visited just after Christmas. I'd met one of the boatmen only last week and he reminded me it was time to make a return visit. The girls are up for it so I run back to the shore and tell the others what we're doing. I grab my bag and Mango Juice Girl comes too.

For comedy value, one of the girls is limping. She'd been run over that morning by a rickshaw. An x-ray confirmed nothing was broken, but until now she had kept her shoe on and had been limping around. Now, to get into the boat she has taken-off her shoes. She is enjoying hobbling around, having a strong arm to hang on to.

On the island we make our way to the guys' hut, under the shade of an enormous tree. We sit around on the bed frames in the yard, lazily admiring the "old Macdonald's farm" collection of animals – this time adding eight running ducks and a couple of geese.

The other two girls go to look around – giving the horned dairy cows a wide berth. Mango Juice Girl and I sit on the same bed. We seem to be very comfortable with each other – it's just the rest of the world who will not let us touch.

By the time the girls return it's time to milk the cows – I naughtily suggest they have a go – of course none of them have milked a cow before. It is fun. Mango Juice Girl declares herself to be the best.

Meanwhile one boatman starts a fire and puts a kettle of milk on to warm; we're going to taste some. I notice the sun is setting. It's large, round and red and quite beautiful. I call Mango Juice Girl to come and watch. In a minute it has gone.

Our friends on the "mainland" will be cold and impatient, wanting to go home. The girls with me had hastily left their possessions on the riverbank. Even if we leave immediately it will take us 20 minutes – I suggest we give them a call and then get moving. The boatmen protest that we haven't drunk the milk and I assume the girls persuade him that we'll drink it on the boat as that's what happens. The waiting friends are not too angry but by now it is quite dark an definitely time for heading home.