Kevin goes all out to create the perfect romantic setting for Valentine's Day. Lucy doesn't want to attend because she had him agree not to propose on Valentine's Day. Eric and Annie convince Lucy to go. Kevin invites all the Camdens, his brother Ben and their mom (guest-star Bo Derek) to be there with him when he finally gets down on one knee to propose to Lucy. Meanwhile, Roxanne overhears Chandler practicing his own proposal to her but she asks him to wait so they won't steal Lucy and Kevin's thunder.

When Dylan is invited to the launch of the first Commonwealth ship made in 307 years, you can tell something will go wrong. As the ship explodes sabotage is suspected. As Dylan and the crew try to find the culprit, they encounter many different suspects while being attacked a violent pride. Can Dylan find the culprit before the Maru is next?

This episode featured four couples competing as teams.

A witness for an up coming case is found murdered. Jordan is sure there is a dirty cop involved in the permanent silencing of this witness. Meanwhile Dr. Macy and Dr. Winslow head an investigation of their own.

When traveling psychologist Dr. Gretchen Trott (guest star Jane Krakowski) comes back into town, Andy is forced to confront his potentially romantic feelings for her. In other romantic entanglements, Edna and Irv have difficulty adjusting to life after his heart attack scare; Harold and his wife Rose (guest star Merrilyn Gann) have it out after they attend couples therapy and she suggests that he's lost that lovin' feeling; and Ephram asks Laynie (guest star Nora Zehetner) out on their first date, in part to show Amy that he's moving on with his life.

Doug cannot spend time with Carrie on Valentines Day, because he has to deliver penguins, with Deacon, from one zoo to another. Yet, along the way, they run into some mishaps. Meanwhile, Carrie and Holly go out and give her tips with men to look for a man for Hall. However, Carrie inadvertently fixes her up with her boss. Also when Arthur and Spence go to up a pick a date for the holiday, he accidentally gets himself a date that is old enough to be his grandmother.

A dead junkie is found on a Miami street with a broken neck and a wad of cash in his hand. When the body is taken to the lab, Alexx notices that the victim's right hand is burned down to the muscle, even though it wasn't like that when he was found. It's deduced that he was exposed to radioactive material. The investigation leads Horatio to an environmental lawyer involved in radiation cases. Shortly thereafter, she learns that she is being eaten up inside by the deadly substance and has only days to live, but she doesn't know how she ingested it or who gave it to her.

Tonight, political columnist and author of The Natural, Joe Klein
Jon begins by reporting on the Michael Jackson alert level being raised from mochaccino to pasty. Coincidentally, John Ashcroft increased Homeland Security's alert level from yellow to orange in a segment called "Warning Sickness". The level rose because of specific information, information that as Jon reports, is not specific at all. Senior Terror Alert Level Analyst Rob Corddry talks with Jon about where that information came from. Jon then looks at New York City's reaction to the new threat level.
Finally, Digital Correspondent Ed Helms reports on how to use the internet to find things wou want in a segment called "Digital Watch".

In a very Intense episode Kath Fox is standing in court on a reduced charge of Assisted Suicide of her husband Terry. Ben Saunders attends a home birth on behalf of Lisa Fox, as a hospital birth has complications. Ben's home birth takes a dangerous turn, and he has to give birth to the baby in the back of an ambulance, This allows Ben to qualify as a registered Midwife. At the Hospital There are a number of power cuts and Mubbs Hussein looses a mother in theatre due to severe bleeding. Tony Vincent spends much of the episode looking for his boyfriend (Ben Saunders) and manages to get cover at work so he can join him later for celebration Drink. However Ben meets up with Greg Townsend, the paramedic from the ambulance and they go off together for a bit. Tony arrives after this has finished so it appears Ben is off the hook.