Detective Sergeant Alex Gregory has found herself prisoner on the slave island run by the mysterious Healthglow corporation. With the outside world convinced she is dead, she is set to join a specially chosen group of slaves on the way to South America and begin a life of toil and torment as a workhorse and pleasure pony under the control of a vicious drugs baron. Her one slim chance remains the unofficial investigation being conducted by her former colleague, DS Geordie Walker. But will Geordie allow the delectable pony-girl Millie and his own newfound interest in human equestrianism to distract him from her rescue?