Wealth of the Void

That a planetoid of solid gold might exist in the Solar System is not beyond scientific possibility, insofar that our own Earth is basic nickel-iron, so might another world - of smaller size perhaps - be of basic god. Such a world is ZK/70, a planetoid in the region of the Asteroidal Belt. Why, when he discovered the golden planetoid, did not Professor Brailsford bring back with him enough of the precious metal or gold dust to make himself financial dictator of the Earth? Why? That is the question.
Instead, he dies without explaining and leaves his space machine and the course to ZK/70 to his daughter, step-daughter and their respective partners. Out to ZK/70 travel the intrepid quartet, each one quite sure what will be one with unlimited gold once they have their hands on it...