More about Castaway Heart: Book One by L.C. Mawson

Lyna had always known that her sister, Dyna, had mated a merman who lacked honour. What she didn't realise was that her sister was going to great lengths to cover up bruises from him.

In the middle of Lyna's one chance to cement their family's future - a ball at which she intends to set up her younger sister with the princess - she sees her sister attacked by her mate, and the two escape Atlantis for Earth - the barbaric land of the humans.

With nowhere to go and no way of getting free of Dyna's mate, help comes in the form of two unlikely friends. A Demon Slayer with a healer's touch and a Human who can see through magical illusions.

Four entwined destinies become entwined hearts as they struggle against the bounty hunters sent to retrieve the two mermaids.