This is just an idea. I'm not sure about it… so review if you want it to be continued into a story. All human... by the way.
Emmett McCarthy is an assassin. However, his cover job is as an agent in a people protection program. What will happen when he assigned to kill the same person he is assigned ton protect… a.k.a. Rosalie Hale.
Carlisle Cullen, Esme Cullen, Alice Hale & Edward Cullen… father, mother, daughter & son
Emmett McCarthy & Bella Cullen… brother & sister
Jasper Hale & Rosalie Hale… brother and sister
Edward Cullen & Emmett McCarthy… best friends
Alice Hale & Bella Cullen… best friends
Jasper Hale & Alice Hale… husband & wife
Edward Cullen & Bella Cullen… husband & wife
Carlisle Cullen: tall, blond hair, gray eyes. Fatherly, smart.
Esme Cullen: average height, brownish hair, green eyes. Very motherly, very kind.
Alice Hale: short, dark hair, gray/green eyes. Can usually tell what is happening, loves shopping.
Edward Cullen: tall, bronze/brown hair, green eyes. Is very aware of the thoughts of others, loves music.
Emmett McCarthy: tall, dark hair, blue eyes. Very muscular, he is also kind.
Bella Cullen: short/average height, brown hair, brown eyes. Very clumsy, loved by everyone.
Jasper Hale: average/tall height, blond, green/blue eyes. Cares about how people feel, deeply concerned for well being of his sister.
Rosalie Hale: average/tall height, blond, blue eyes. Can be rude, but she loves little kids.
Emmett: he is an assassin, but nobody knows. Instead, everybody thinks that his real job is the cover job he has, an agent in a people protection program.
Rosalie: singer/actress. The reason she needs protecting is because her ex wants her dead and nobody else does… especially her fans.