When Lou encounters some trouble, Nick and Jacob start up the hot tub time machine again in order to alter the past, but accidently end up in the future.
The Jokers head to Raising Cane's where they raise mayhem and then ask for help carrying furniture; later, the loser gets strapped to a fast-moving race car.
The conclusion of the "what if" episode shows Ross having a threesome with Susan and Carol, Rachel kissing Joey and Monica and Chandler hooking up regardless.
Ross ponders dating a student who is smitten with him, even though it could cost him his job; Rachel moves in with Joey after her apartment burns down.
Joey's fridge is broken and he tries to cajole his friends into helping him buy a new one; Phoebe, Monica and Chandler compete to get Rachel a date for a ball.
Ross asks his friends to keep him company when he meets Elizabeth's dad for the first time; Joey may get fired when he fights with C.H.E.E.S.E's operator.
Chandler tries to make Monica think he doesn't want to get married in an attempt to surprise her with the ring; Richard proposes to Monica at her work.
Planning for the wedding begins; Phoebe moves in with Ross, bringing her massage parlor with her; Monica's parents spend the wedding money on a beach house.
When a female physicist stays at the guys' apartment, Leonard and Sheldon compete for her attention, and Penny is bothered and upset by their behavior.
After realizing he won't live long enough to download his consciousness into a robot, Sheldon tries to extend his lifespan by reducing his contact with people.
An embarrassing incident Howard has tried to keep a secret comes to light as he attempts to win back his ex-girlfriend; Sheldon and Raj have a war at work.
Leonard asks for help when he realizes he is the only one in the group without a girlfriend; after meeting her mother, Sheldon tries to get rid of Amy.
Leonard tries to keep a secret from the guys, but when Sheldon uncovers the truth, he helps Leonard by making up a story to keep the others from finding out.
The Jokers ask strangers if their radio ad is good. One joker will be getting revenge in an elaborate punishment that the other two are really going to feel.
A woman and her boyfriend from a colorful world get the chance to go to the real world, but they soon discover the joys and perils of living among humans.
Jay and Claire butt heads over how to make a Pritchett Closets commercial; Phil, Luke and Manny plan to stop a neighbor who is using a drone to spy on Gloria.