We ask a few people in the street where we can find Marcelo and his internet cafe. It's closed down, but we are pointed in the rough direction. Finally, someone shows us the house he lives in. It's a bare shell of a building. Plaster, concrete and just a few windows in place.

Inside, Marcelo is sitting behind a desk in a room with piles of books, a computer, some sweets and little else.
He's younger than i thought and bright eyed. The internet cafe closed a while ago, he says.

Leandro slowly starts to ask about El Dorado. Marcelo nods, then just starts to talk. It's hard to do justice to the long, long flow of his speech. Of the rambling connections in his hunt for El Dorado. Of his theories, his expeditions and his desire to live on in eternity. He spoke quickly, but repeated long sections. Leandro updated us and I followed lots (two years living with a Brazilian means I can listen to them) but I am sure details are lost.

The basis of his theory is that a tribe that pre-dated the Incas, Mayas and other south american tribes existed. White faced people living in Brazil. That these people's great city was the El Dorado that the conquistadors failed to find.

He was planning another expedition for later that year. Out back were bags of expedition kit - pans, machetes, tins etc... And the boat they would sail with. He wanted to wait until he got a better camera before he left, he said. In the meantime he seemed to be living from expedition food and little else. Half eaten tins lay around. There wasn't anything else in the house.

He'd sold everything for these expeditions, he told us with a manic look. The first was in 2004 (looking for El Dorado in particular) and since then he'd sold his house and everything he owned. Soon, someone was coming to take over this house from him. Later, with a twisted laugh, he said how mastercard and visa and amex had all stopped his cards and that he owed them 120,000rs (£30,000). An unpaid phone bill laid under his computer mouse.

The proof seemed like big jumps of imagination to us. Faces in stone that were hard to see. Supposed carvings in the rock face that showed white faces of a long lost race. From there his story ranged from the high plains of the Amazonia via Macchu Picchu (the hidden stories and carvings that Bingham denied the world) to the bible and he source of Solomon's riches. With each step the theory took it became harded to believe and Marcelo seemed even more disconnected. I wanted to believe him in some way as he said to us "What else can I do if I have sacrificed everything for this?". It was saddening. He'd spent everything and now had no choice but to follow his path.
His expeditions (he showed us photos and password-encrypted excel sheets) looked shambolic. A ramshackle group accompanying him for 150rs a day. He said that those who quite (and there seemed to have been plenty) were never again to be trusted.

The film had been taking shape in my mind, but now I wasn't sure. It would be too easy to show him as crazed. How could we play it straight and fair to him?
It didn't matter. He didn't want us to film him.