When a day out in 21st Century London leads to the TARDIS being impounded, the Doctor and Leela find themselves getting involved with the mysterious Amapan Investments, a company that’s managed to become remarkably successful in a remarkably short amount of time. So what’s their secret? The Doctor and Leela are about to find out. The Usurians have come to Earth. And they have big plans. Note: This title is also available on CD as part of Doctor Who: The Fourth Doctor Adventures Series 10 Volume 01