Another week, another case and Castle (Nathan Fillion) is still no closer to winning back his wife (Stana Katic). In episode 4 of Season 8 of ABC's "Castle," he was able to solve both a murder and a case of mistaken identity, but that did nothing to woo the stubborn Beckett. In fact, it only earned a diss on his favorite book! Will anything be different in episode 5, "The Nose"?

The synopsis for the new episode says a priceless work of art will be stolen and the crime will leave a man dead. Castle will be on the case and will have to rely on the only witness for help. The only problem is that the witness is more of a nose-witness than an eyewitness. A woman played by guest star Stephnie Weir ("The Comedians"), with a keen sense of smell believes she can sniff out the murderer. That may seem a little strange, but Castle seems game and, hey, stranger things have happened on the show.

Plus, Castle's prized new witness might be able to help out with the writer/private investigator's other big problem: his wife. The promo for the episode reveals she believes she can smell Beckett's still-very-intense attraction to him.

"She's clearly got the hots for you," the woman promises.

For Castle, that's good news, but can the mysterious witness' sharp senses be trusted?

Watch the promo for episode 5 below:

Will Castle ever win Beckett back? Fans will have to wait to find out. "Castle" airs Mondays at 10 p.m. EDT on ABC.