Mystery of the lost English explorer

The Guardian has the low down on an explorer who disappeared mysteriously after searching for the lost city of Z in the Brazilian struggle. The story is equal parts "Heart of Darkness" and "The Lost World" with bits of "She" thrown in.

'This is one of the great adventure stories of the past century,' said Williams, 'and at last we are finding out what really happened. Fawcett was a kind of Indiana Jones figure and his children have fought hard to keep his good name, in spite of interest from Hollywood and countless books.
'His secret plans for a new and unconventional way of life have only just emerged from the letters he wrote to friends.'