Answer:
Lennie has killed the puppy
Lennie becomes so angry that he hurls the dead puppy across the barn. Shortly after having thrown the puppy, Lennie picks it up again, stroking it and deciding that maybe George won't care. Curley's wife enters the barn and asks Lennie what he has.
Lennie is scared that George will not let him take care of rabbits when they get their own land, while Curley's wife is scared for her life. Lennie kills Curley's wife, and then Curley declares he will kill Lennie in revenge