After leaving Saturn the Astronef pursued her lonely course on her homeward voyage across the fields of space, while the Ringed World, which had so nearly proved the end of Lord and Lady Redgrave's wanderings, grew dimmer every hour behind them.

On the morning of the fourth day from Saturn, Lord Redgrave went as usual into the conning-tower to examine the instruments and to see that everything was in order. To his intense surprise he found, on looking at the gravitational compass, which was to the Astronef what the ordinary compass is to a ship at sea, that the vessel was a long way out of her course.