This episode starts off with Zoey and Ted kissing. Ted tells Zoey he's ok with taking things slow because he thinks she's going through a lot, saying he wants to do things right between them. On telling his friends about it they are not so supportive with him taking things slow. Barney tells him he's doing it all wrong while Lily tells him that they are couples in her kindergarten class who are faster than them. He then informs them that he has been trying to fix some dates but she keeps cancelling and that she wants him to come over to her house to bake cookies. Robin, Lily and Barney make it clear that it's a booty call.
Meanwhile Marshall leaving is beginning to have a weird effect on Lily cause its been a long time he has pleased her, and the fact that he's not going to be there with her on Valentine's Day to continue a tradition they both started since they were dating in college i.e. watching Predator.
Also Barney is excited not about Val's Day February 14 but about the day before Val's Day February 13 because he thinks there would be lot of desperate chicks looking for a date for Val's Day. He called it Desperation Day, hence the title. Although there is one thing you must not do according to Barney "wherever you are or whoever you are under you must get home alone by 11:59 otherwise you're on a date on Valentine's Day." Robin disagrees with him.
Lily decides to go to Minnesota to see Marshall because she thinks she's getting weird cause she turned her body pillow into Marshall. Ted tells his friends about his night and how it went badly because he took an overnight bag and Zoey thought he was being too presumptuous.
On getting to Minnesota, Marshall was so surprised to see Lily, but Lily was more surprised to see that Marshall had turned into a kid who just bossed his mom around. Marshall's mom told Lily to get him out of her house, Lily tried all she could but nothing seemed to be working. She then tells Marshall that his mom wants him out when he asks his mom she denies it so he feels like his mom still needs him so he can't go.
Back at New York, Zoey apologizes to Ted about what happened the previous night and Ted forgives her and they share a kiss. At MacLarens while Barney acts as a predator looking for who to devour i.e. the ladies Robin tells Ted that his relationship with Zoey is already pretty serious even though they just started going out. Ted panics and goes down to Minnesota saying he came to help Marshall but really running away from spending Val's Day with Zoey.
Also back at New York, Robin and some friends of hers from work are at a get together of girls who hate Val's Day and decide to wear purple to protest the day. Barney thinks that they are all just weird and lonely. Then enters Nora who incidentally isn't wearing a purple shirt.
Instead of helping with Marshall, Ted just seems to be turning into a child just like Marshall. Lily pleads with Marshall to come back with her to New York he refuses. She tells him she is leaving he begs her to stay but she insists and tells him to please come home soon.
At MacLaren's Barney is still trying to hit on insecure dateless girls he already had one and told her to get ready for them to leave. Before leaving Barney asks Nora why she wasn't putting on a purple shirt also she says she loves Val's Day and doesn't agree with her friends. Barney lies to her that he also loves Val's Day but she saw through his lie and told him that she know he's just doing it to get into her pants.
Marshall tells Ted that he misses his dad a lot and that's why he hasn't returned to New York yet. He tells Ted a memory he has of his father where they are taking a family trip and its pitch black and he's scared but his father always made him feel safe, he felt like his father was some kind of superhero and now he's just gone. They both then decide that running away and hiding out is not good so they should drive out to New York because there are no more flights.
Barney hits it off with Nora he tells her about Desperation Day and about Laser Tag they go on and on and he also ditches the girl he was supposed to sleep with. They head to meet Robin and they realize the other two girls left with some dorks. As Nora leaves Barney begs her not to go but she tells them she has a date with her pillow and then she leaves. Robin points out to him that it's past 12:00 so technically he broke the rule of Desperation Day. She tells him that he likes Nora but he denies it, she also plays a trick on him to prove that he really likes Nora.
Meanwhile, as Marshall and Ted drive down it's pitch black, Ted's asleep and Marshall can't see a thing he sees his father who tells him that he also couldn't see a thing when they went for those trips but he should just keep going forward.
So at the end on Val's Day Ted and Marshall were on time to spend their day with their women, Ted with Zoey and Marshall with of course Lily. Then Robin who was supposed to be Barney's laser tag teammate called him up and told him there was a change of plans his teammate would be Nora instead, so technically Barney had a date on Val's Day too.
At the end Lily broke up with the body pillow she called Marsh-pillow.