Forbidden is a novella in Kelley Armstrong's Women of the Otherworld Series. Chronologically the story takes place sometime after Elena and Clay's trip to Alaska as told in Frostbitten.
During their time in Alaska Elena and Clay met a werewolf named Morgan who was experimenting with living full time as wolf and running with a real pack of wolves. Now that I think about it, he sort of reminds me of Elena in the first book of the series when she was trying to live her life exclusively as a human. She wasn't ready to accept her new life as a werewolf or give up her "normal" human life and resisted the change into her werewolf form as much as she could. Morgan does the exact opposite but both were trying to suppress a part of their identity.
Morgan's family seems to have felt the way Elena used to feel about being a werewolf - that it was a curse. Morgan went along with that for a time but then rejected it and decided to embrace his wolf side wholeheartedly. He liked being a wolf but found he missed intelligent communication involving words. Morgan had heard of the North American pack, currently headed by Jeremy Danvers, but worried about joining it. There are benefits and drawbacks of being part of a pack and having to follow a leader. (Interestingly, this is a subject currently being addressed in season two of Bitten, the television adaption of Armstrong's series.)
After meeting Elena and Clay, Morgan begins to flirt with the idea of joining the North American werewolf pack. Morgan is on his way to visit Stonehaven, the Danvers compound, when Forbidden begins. Morgan stops at a diner in a small town for some meatloaf and pie and later wakes up naked in the snow. He swears he wasn't drinking. One of the primary objectives of Elena as Jeremy's second-in-command, and really all werewolves, is to keep the fact that they exist a secret from humans. A werewolf in jail for too long would ruin that since a werewolf must change periodically. Elena and Clay travel to the small town to get Morgan out of jail and remind him of the danger of exposing his wolf to humans. It was supposed to be a quick trip: bail Morgan out of jail, enjoy some adult time alone away from their five-year-old twins, and then return home. But after bailing Morgan out of jail Elena, Clay, and Morgan find that their tires have been slashed. Later they're stumbling through the woods and come across a dead body, tribal looking marks on a tree, and a cave with old bones, some animal and some human. Is there a man-eating werewolf on the loose or is a human behind it all? Elena can't leave without making sure a werewolf isn't responsible, and of course Clay won't leave Elena.
This was a quick, fun read. There was a little bit of a mystery. Mostly it serves to further introduce Morgan to the pack and to show how Elena is preparing for her eventual and inevitable ascent to pack leader. There are three more books in the original series (not including the anthologies, novellas or comic book) and I suspect Elena will become pack leader in the next book. If your a fan of the Women of the Otherworld series definitely read this. If you're new to the series, start at the beginning. It helps to already be familiar with the characters before encountering this one.