The Silver Collar (Black Lace)

Eleven years ago a powerful ancient werewolf ripped Iris' life apart. One full-moon night it attacked the two people she loved most in the world, killing her twin brother Matthew and leaving her boyfriend Alfie changed forever. Iris and Alfie vowed revenge on the beast; but when Alfie began to show a twisted loyalty to the creature who had made him, Iris lost him too. Now, Alfie is back in Oxford where Iris—still haunted by her dead brother—is heading up the Vix, a shadowy organization dedicated to killing his kind. But Alfie needs her help or what the beast did to him that night may yet prove fatal. His body is fragmenting—the rules that govern his transformations into a wolf are changing. His only hope of keeping his deadly beast under control is the Silver Collar, an ancient artifact currently owned by the Vix. But Iris isn't prepared to help Alfie secure it until he agrees to defy the rules of his kind and help her avenge Matthew's death. Alfie and Iris both think that what happened between them 11 years ago has destroyed the love and trust they had for each other forever, but the Silver Collar shows them that they're both wrong.