Reeling from the deaths of their respective sisters, Piper, Billie and a returned Leo enlist Coop's help to go back in time and prevent all the misguided bloodshed. This forces Billie to realize just what her sister had truly become. The future versions of Chris and Wyatt also make a helpful appearance. When everything is said and done, the Charmed Ones are left to reflect on all they've experienced during their time together.

Autopsies on two dead deer lead NorBAC to suspect that worms from parasitic eggs are responsible for a recent spike in depression-related suicides in the Southern U.S. What they can't figure out is if the parasites are coming from the deer, humans or a third source.

While working on a retrovirus, Jill becomes contaminated and is forced into quarantine.

Owen is charged with criminal negligence when a young girl dies after overdosing on crystal meth. David comes to his defense, arguing that Owen is predisposed to being an addict. The defense sparks a fascinating legal, scientific, and ethical argument.

Homer and Marge offer up martial advice to the Springfield Isotopes struggling first baseman, who is having problems with his pop star wife.

After losing at a swim competition, Stewie trys to eliminate his rival by blowing up a lifeguard tower. His plan backfires though, and Stewie has a near death experience that seems to change him.

Both Bill and Barb get social recognition as Barb is selected as a finalist for a "Mother of the Year" award and Bill is asked to become a member of the Salt Lake City Leadership League. Meanwhile, the sister-wives draw up their wills, and Rhonda gets to know what life outside the compound is like for teenage girls when she hangs out with Sarah and Heather.

When the victim's credit card is suddenly used a year after his death, Lilly re-opens the 2005 case of a counselor at a teens' rehab center who was shot to death just two weeks before he was scheduled to testify in a murder case. During the probe, Lilly feels a strange connection to the victim, and her personal attachment may end up jeopardizing the case.

Flashbacks (featuring special guest star Steven Culp) take us back to moving-in day on Wisteria Lane for Bree, Lynette, Susan and Gabrielle and how Mary Alice brought them all together. Also, in other flashbacks we are taken back to the day Melanie Foster was murdered. Back in the present, Bree gets some frightening news. Susan moves into a trailer after her house was burnt down. Lynette and the kids are staying at a hotel. After seeing a report on the news, Gabrielle believes Carlos died. Paul begs Zach to get him a good lawyer via Noah.

Flashbacks (featuring special guest stars Steven Culp, Jesse Metcalfe and Roger Bart) take us back to key moments in time for Bree, Lynette, Susan and Gabrielle and how they connect to the present. After hearing Betty's message on her cellphone about Matthew being a murderer Bree realizes she needs to escape from the psychiatric hospital and help Danielle, who has run away with him. When he sees Mike buying an engagement ring, Karl buys Susan a house. Lynette finds out that Tom has an illegitimate daughter from before they were married. Gabrielle discovers a shocking secret her husband has been keeping from her.

Stewie convinces Brian to go on a road trip with him to San Francisco to search for a man Stewie believes is his real father.

Carmela begins to rethink her life after she goes out for a day with Rosalie. Meadow decides it's time to find a new place to live. Tony and the gang suddenly find themselves in a place they have never been before - lacking funds.

Lahey appears before the police board. Julian prepares a surprise for Ricky. Ray becomes Assistant Trailer Park Supervisor.

Stewie finds out that his life in the future is miserable. So he decides to go back in time and change events for the better.

Huff has become ill, both emotionally and physically, because of his relationship with Beth. Some of the things Teddy has told others about his relationship with Alyssa finally catches up with him. Russell fails to a keep an important promise that he made to Kelly. Meanwhile Ben's attempt to reach out to Izzy fails.

Leonardo, Raphael, Michaelangelo, and Donatello adjust to life in a nursing home in "Senior Mutant Ninja Turtles". Cloud and company work hard in a fast-food joint in a spoof of "Final Fantasy VII". And Bugs Bunny is Sorry B Rabbit in a send-up that combines "Looney Tunes" and "8 Mile".

Segment #1 - Rihanna and her friend stop and hear some street performers and when her friend puts in a $100 instead of a $5 they exchange it and the kids accuse them of stealing so Rihanna puts in a $10 and walks away. The uncle gets the cops and they tell her she's going to jail so she wants to give them the $100 and her album.<br />Segment #2 - Hugh Jackman gets a tour of a director's house and is asked to turn on the grill but nothing happens so they leave for a restaurant only to return to the house on fire. Firefighters tell them that houses next to it are caught on fire as well. They tell them they need to go downtown for questioning.<br />Segment #3 - Eric Dill and his band are at a bowling alley and they get yelled at for crossing the line and goofing around then Eric rolls the ball and right as it gets to the pins the metal bar comes down and breaks. Then he gets blamed for ruining a birthday party and a 300 game. An employee threatens Eric by saying he would be the first guy he beat up since he was released from prison.

Tiff Needell test-drives the latest Corvette, and Vicki Butler-Henderson goes undercover to sneak a look at the new Aston Martin, soon to be seen in the next James Bond film. Tom Ford visits Japan to examine a groundbreaking Japanese car that runs on hydrogen, while lawyer Nick Freeman, who specialises in celebrity speeding cases, discusses his work.

The return of one of Gerry's informants leads to the team re-opening a botched bank robber, which left a cashier dead.

The prime suspect at the time is now a celebrity - is he a suspect, but was he responsible, or is he as innocent as he claims?