The Rejected Twins

Luna and Misty are werewolf/vampire hybrids. Which means they are a disgrace to their pack. Their mother was killed for mating with a vampire and they were used as the pack's slaves for years until their 16th birthday when they were supposed to find their mates. They ended up getting rejected and they leave but are soon accepted into a pack that is nothing but hybrids. 

Just when they start to finally feel at home, their old pack needs help, and their current pack ends up having to go help.