Rossi takes a few days off to meet with his third ex-wife, Krystall Richards. Two women in Chicago have been stabbed in the back, with red roses placed in their mouths. The unsub then kills a third victim. Krystall is in town for her daughter Portia's wedding. Krystall invites Rossi to the wedding as her plus-one. Portia's fiance Wick is snappish toward her, and Rossi gets suspicious. The unsub claims a fourth victim. The unsub is bringing an item representing a song title to each killing. Rossi has Garcia run a background check on Wick. The unsub is connecting with the women late at night. Simmons suggests he might be a DJ. The unsub seems to be Craig Kaline, a DJ who is about to renew his vows with his wife Cheryl. Kaline plays love songs from the '30s, '40s and '50s. Wick has engagements to three women in three years, all of which fell through, and he walked away with money each time. Reid figures out the unsub is growing roses. Craig's girlfriend Janice is threatening to tell his wife. Garcia locates Craig's show. They find Craig dead at Janice's home. Rossi and Krystall tell Portia what he'd learned about Wick, and she storms off. Cheryl is holding Janice hostage at gunpoint. Cheryl picked her victims from Craig's fan-mail box at the radio station. Cheryl takes Janice to the site where she and Craig were going to renew their vows. Simmons convinces Cheryl that Craig's final show is playing all around her. Wick comes to Rossi's house to gloat because Portia has agreed to go ahead with the wedding. Rossi threatens to sic a psychopath on Wick and Wick walks away from Portia. Krystall comes by to tell Rossi the wedding is off again.