Desperate Housewives

Back in season 4 Nathan Fillion portrayed Adam Mayfair, husband of Katherine Mayfair (Dana Delany). He was a gynecologist from Chicago who delivered Danielle's baby and ended up returning to Chicago at some point.

We've seen Betty Applewhite in the first two seasons, playing a former concert pianist and mother who would do anything to protect her family.

John Barrowman played Angie's husband Patrick Logan, who has been on the run for almost 20 years. He holds his ex-wife hostage, wanting her to build a bomb for him. She tricks him and... let's just say it didn't end well for Patrick.

Shirley Knight portrayed Phyllis Van de Kamp, Rex' mother and Bree's mother-in-law. She drops by, much to Bree's dismay, for the funeral of her son. They don't get along quite well and Phyllis returns in season 4 for the baby shower.

Robin is a former stripper who used to work in a club that ends up being Susan's when her ex-husband dies. She later has an affair with Katherine and they go to Paris together.

Nina is Lynette's boss in an ad agency in the early seasons.

Keith re-decorates Bree's house and they soon develop feelings for each other, having an affair. The whole thing ends after a while when he finds out that he has a child and Bree encourages him to be with his child instead of staying with her.

Orson's former neighbor suspected him of having murdered his wife Alma. She becomes quite obsessed, trying to warn Bree several times. She later holds a few people hostage which resulted in her death.