Slave Exodus

When Detective Sergeant Alex Gregory has a nasty parachuting accident, it should be the end of the line for her. But when she wakes up in a new body she realises she's been given a new lease of life. Unfortunately her captors have very unusual tastes, including one for human pony racing. Alex's home is now a Spartan stable, her only clothing an elaborate harness, with a bit that ensures her silence. Will her colleagues ever be able to rescue her?