Anyway, I am trying to move on, helped by the patriotically attired crew of British Airways who moved me to a seat with extra legroom. I can’t help having legs that go on forever.

This is my longest assignment to date – in terms of haul, not legs of course – and to Brazil’s first capital I go, on a mission that I hope will have a very sweet ending.

My destination is La Villa Bahia in Salvador’s historic centre, Pelourinho. It is a colonial hotel, made up of two yellow-fronted houses that date back to the 17th and 18th centuries.

It is simply charming. There is antique furniture, bathrooms with shiny brass sinks, brightly coloured curtains and wooden floors throughout. And there are just 17 rooms, all named after the old Portuguese colonies from along the spice route.

I’m in ‘Goa’ sleeping on what I’m told is a 200-year-old bed. I suppose some might find getting shut-eye on a relic a little odd, but I am of the Old World and at home I sleep on the bed my great-grandmother died in. So this is pretty much home from home, or bed from bed – although, I might add, it’s more likely the death bed of a slave trader than a granny.

After the Spanish, the second largest foreign community in Salvador is that nation famed for making penknives. And their reason for being here fits in nicely with stereotypes: chocolate.

Be ashamed of yourself if you haven’t guessed I’m talking about the Swiss. They own cocoa bean plantations near Salvador and factories in the south of the state of Bahia.

“Reclaim what is rightfully ours,” said HQ, in typically enigmatic turn of phrase. It took a couple of caipirinhas, but I think I sussed it out.

In the 18th and 19th centuries the British came over to help the Portuguese industrialize Brazil. As far as I can tell, Portugal owed our Empire money, so we came to claim what was rightfully ours.

And that’s exactly what I’m doing here – reclaiming a chocolate plantation that is legally British. I’ve just got to find the paperwork to prove it.

Stocking up on the famous Villa Bahia breakfast (coconut tapioca pancakes, fried cinnamon bananas and the choice of six different types of Brazilian coffee), I venture out into the cobbled streets and make my way to the Convento do Carmo.

Now a smart hotel, this was a former 16th century convent, and the nuns who inhabited it were also the custodians of the warrants for all the sugar plantations. But when the convent changed hands and was in the process of being refurbished into a hotel, a clandestine deal was made and a British plantation was sold to a sweet-toothed Swissman.

The Swiss say they thought it was Brazilian. So, to rightfully reclaim it, I need proof. Nodding hello to the smart doormen, I enter the high-ceilinged hotel. With open courtyards, heavy wooden doors and stone walls and floors, its former days don’t seem so far away.

I walk past the reception to a courtyard with a pool in its centre. It has an unusually high curved edge, which I walk round and perch on as though having a little rest. Leaning over I tap my nails against the stones until I find the right one.

Nudging it from side to side it finally slips free and I reach a hand into the dank entrails. I glance around to check no-one has clocked me. A few people sit eating breakfast, but they show me no interest. Ah. Bingo. My research (trans: lightly throttled museum curator) has paid off and a hidden scroll, wrapped in leather, meets my fingers.

Putting my trusty BB (Hermes ‘baguette bag’ from a previous mission in Paris) on the floor, I let the scroll drop in and quickly replace the stone.

Taking my time to look at the impressive surroundings (like a normal gaping tourist), I make a bee-line for the door and head back to Villa Bahia.