Samantha is once again working to protect the local mustangs in the third book in the Phantom Stallion series. Dark Sunshine finds Sam unexpectedly coming across some horse rustlers. While she is out riding on her own mustang Ace, she stumbles across them and manages to stay hidden. After they have moved on, she is able to free one of the horses they are ill-treating and using as bait for other horses. Sam is keen to do something to save the others.
As Sam works to uncover the mystery of who the men are, she is surprised to find that their property River Bend Ranch is branching out. Her father Wyatt Forster is entertaining the idea of a pilot program for at risk children and rescued mustangs.
Sam can’t see how it will work on their farm – don’t they have enough to do already? Plus, she isn’t sure she likes the young girl Mikki who is to be the first at risk person to try out the program at River Bend Ranch.
Sam finds that Mikki is full of attitude, defensive and rude. The thirteen-year-old can’t see she should want to help Mikki or why she would want to share her father, Jake, Gram and the horses with her.
As Sam starts to make ground with regards to the horse rustlers, she fears she is losing a part of her father to another female. It seems too that Jake is investing his energy in Mikki. To top things off, Sam doesn’t seem to be making any progress with the buckskin mustang she has rescued. Dark Sunshine is a great follow on in this series. Sam develops further as a character and there is a little mystery thrown in to keep things entertaining.