Sex Beast (Savage Shifter #1) by Janelle Oberlin
After a plane crash strands her on an island, U.S. Marshal Heidi Anders must submit to her prisoner, a powerful and dominant shapeshifter. Leaving the civilized world behind, Heidi embraces her primal urges, and learns the freedom and ecstasy that only submission can bring. Sex Beast is an explicit tale of BDSM romance, and is the first book in Janelle Oberlin’s “Savage Shifter” series.