"We should go find a deer" Dean says, his face somewhat paler than usual. "If you keep going we should see some soon".
Squashed into the back of the car I say nothing, watching the lodge go past with a little shiver of panic. After all, of all the jobs I have to do, surely getting Dean to the ceremony on time is somewhere near the top.
But, I counsel myself, it will be okay. We will find a deer within a few minutes (this is, after all, a deer park) and then turn back.
"There's one!" Dean exclaims.
We all look in the direction indicated. There is no deer, just a rather large dog. Somehow I do not think this will count.
The road branches in front of us.
"Go left!" Dean says "It brings us back round".
Given that I have no idea of the geography of this park I decide to lay my faith in Dean. Not only does he have a Rain Man sense of direction, he has also been here before.
Five minutes pass. We are still driving down the road. There is no sign of anywhere I recognise even remotely. This, clearly, is what happens when you put your faith in someone whose emotional state is such that they can mistake a dog for a deer.
I cannot hide my sense of rising panic. I envisage Director Boy ringing my mobile, the mobile that is currently in History Boy's bag and is therefore probably at the ceremony before I am.
If we are lost in Richmond Park, without methods of communication, I think I will officially go down in history as the worst best wo-man ever.
Dean, however, is more concerned with deer (of which there are still none). I wonder if the ceremony will be allowed to go ahead if we fail in the quest to find any.
If I were a praying woman then this is where I'd break one out.
As I'm not, I settle instead for searching frantically for both Deer and a landmark I recognise. I am not sure exactly which one I want more.
And then - as if it had been planned all along - we see them. Dotted across the landscape, oblivious to our car and the significance of the impending day, there are deer as far as we can see.
I hear my voice, independent of my control: "We can go back now?".
It is a question that needs no answer.