"This Won't Hurt an Ed" is the 13th episode of Season 5 and the 115th episode of Ed, Edd n Eddy. In this episode, Eddy and Ed find out Kevin has a fear of needles through his medical file. They then decide to put this to their advantage by declaring to the other kids that it is Booster Shot Day. Kevin after finding out about this tries hard in hiding this secret, but Ed and Eddy do everything they can to make sure that he can't.
Ever the altruist, Edd has volunteered his services to the school nurse and become her assistant, and he is organizing various tools of the trade while his bored friends stand by. Of course, neither of them are very patient, and they cause disturbances until Eddy suggests they go for lunch. Ed agrees with this, as it is Whopper Wiener Wednesday and he wants to get a few wieners in him. Edd agrees, noting that some nourishment wouldn't hurt, but turns back to his work when he notices something out of place. Eddy is annoyed by this, and his annoyance level is only cranked up another notch when he hears a ruckus outside; apparently Kevin made 100 free throws in a row in gym today, and everyone's treating him like a hero. Eddy complains about this, and ignores his friends' attempts to mollify him until a misguided attempt by Ed sends a shelf full of student files crashing to the ground in a heap. While Edd hustles around gathering up the files, Eddy finds Kevin's file and begins reading it, quickly discovering Kevin apparently has a fear of needles, which he, of course, reveals to his friends. However, Edd gets mad at Eddy for reading Kevin's personal file and even tries defending Kevin by pointing out that having a fear of needles is actually pretty common. But by the time he's done talking, the other two Eds have already left the office as Eddy has come up with an idea to prank Kevin.
In the cafeteria, Kevin's victory party is still going strong, with Kevin even going so far as to autograph Jimmy's hot dog with ketchup. Even the appearance of Ed and Eddy in nurse outfits doesn't rile him to anything more than a mocking comment. Suddenly, the party stops, however, as Eddy mentions that it's Booster Shot Day. Ed shuffles out some leaflets, and the kids begin to worry about the needle. To drive the point home, Eddy mentions that Rolf's wiener looks dangerously hot, and pokes it with a sharp meat thermometer. Seeing this, the color drains from Kevin's face and he falls backwards, knocking his chair over.
Soon, though, Kevin gets up, and with a half-hearted excuse about the coach calling him, exits the lunchroom. Eddy begins to gloat, but none of the kids pay any attention, as they're too busy panicking themselves. Even Ed gets in on the panic, dragging Eddy out of the cafeteria to escape the needle he believes is coming for him. Eddy is able to stop his friend and remind him what's going on, however; when they see Kevin walking down the hall, Eddy grins and declares round two is on.
Kevin heads into a bathroom to try and calm his nerves. He splashes some water on his face and gives himself a pep talk. When he looks in the mirror, though, his eyes are drawn a few inches upwards to a ghastly picture of someone taking a needle straight through their arm. Seeing this, he stumbles backwards into a stall. He shuts the door behind him just as Ed and Eddy enter the bathroom, talking about sterilizing big, sharp needles. Kevin's heart is beating fast as he looks up and sees an air vent. Thinking quickly, he escapes into the vent. Naturally, Eddy notices, and he and Ed chuckle at how well their prank is going.
Kevin crawls through the vents, frantically trying to escape. When he comes to the first corner, though, he gets even more freaked out, as Ed sticks his head through a vent in their, revealing himself to have taken a needle straight through the brain. While Kevin crawls away as fast as he can, Ed ducks out, and he and Eddy laugh before Eddy mentions that he has another idea for how to continue the torture.
Edd, meanwhile, has finished his work in the nurse's office and is heading to the cafeteria to get some food when he runs into Jonny, who is bent over in front of him. Jonny pulls down his pants and says that he's ready, much to Edd's shock and revulsion. After instructing him to pull up his pants, Edd hears Nazz in the background, calling her mom to tell her she loves her, and sees Sarah pushing an armor-clad Jimmy forward and warning about how the needles can supposedly put a hole through a truck tire. Things get stranger yet when Rolf accosts the sock-on-head Ed-boy and gives him a jar of his father's stuffed olive pits and begs that the injection be as quick as possible before joining the line in the gym. Edd becomes more confused than ever when he reads on a poster that it's Booster Shot Day, and he checks his calendar, sure that the day is a long way off.
Eddy has been busy with Ed all this time, and they've built a giant replica needle. When they find Kevin, they threaten him with it, and Kevin is backed into a corner by the nurse's office, strung out on fear and adrenaline. Suddenly, Edd jumps in and tells Eddy that there are no vaccinations scheduled for today. Hearing this, Kevin's heart rate slows to normal and he starts to realize he's been duped. When he sees the makeshift needle, Edd quickly realizes what's going on and angrily accuses Eddy of defrauding the whole school for his own self-gratification–and this only becomes more evident when Jimmy spots the giant booster shot and warns the other kids, who panic and run out of the gym. Eddy still believes that he has Kevin nailed, though, and he demonstrates to Edd by poking Kevin's arm with the shot. As it turns out, though, Kevin has realized that he's been tricked, and is ready to beat Eddy into little tiny pieces with a golf club that formed part of the needle. Scared, Eddy pulls Edd in front of him and begs for help, and Edd is quick to offer it, by giving Kevin an alternate solution to his problem. You see, in a surprisingly devious move, Edd was able to convince the nurse to help Kevin get over his fear of needles by giving him a demonstration of a safely applied booster shot, and offered up Eddy as the recipient of the shot to even the score with Kevin.
Eddy: [dispassionately watching Ed inflate his face with the blood pressure cuff] "Gee, nice head, Ed!"
Edd: [looking despairingly at the mess on the floor] "Oh dear. Do you have any idea how long it took me to arrange in alphanumerical order those confidential student files, Ed? Do you?" Ed: "Was it longer than a bread box?"
Kevin: [incredulous as Rolf kicks him] "Hey man, what gives?" Rolf: "Rolf honors Kevin with the Posterior Punt of Praise!"
Jimmy: [looking adoringly at Kevin] "He's so dexterous!"
Kevin: [mocking Eddy and Ed's medical outfits] "Well, if it ain't Florence Dorkendale and Nurse Twerpenstein."
Ed: "Tell 'em to line up in the gym, bonehead! Did I do good, Eddy?" Eddy: "Shut up, stupid!" Ed: "That's my line, Eddy."
Ed: "Needles!? Run away! Evil! Pointy! Bad for Ed, Eddy!"
Eddy: [trying to freak Kevin out] "We'd better sterilize these sharp needles, Ed." Ed: "Say they're big, monobrow!"
Rolf: [groveling in front of Edd] "Double D Ed-boy, Rolf begs you, take this jar of Papa's filled olive pits and be quick with your pain-filled poke!"
Ed: [sagely] "A good buttock finds its own bench, Eddy!"
Eddy: [as he gets his shot from Nurse Prowse] "I hate needles!"
Jonny: "Me an Plank are next, nurse assistant Double D!" [He pulls down his pants, exposing himself to Edd.] Edd: [frantically covering his eyes] "GOOD LORD, JONNY! MAKE YOURSELF DECENT, MAN!"
Eddy: "Who's the big shot now, huh?! Get it?! Big, shot?" [laughing menacingly] "I'm too good!" Kevin: "That was really funny, dorky! So I guess it's my turn, right?" [grabbing a golf club] "Kiss your face goodbye, loser!"
When Edd replaced the box of wooden sticks after Eddy contaminated them with his earwax, Edd had only one box of wooden sticks in his hand, but when the camera angle changed, he had two.
If you look closely when Ed launches himself out of his pants, he is barefoot. However, when he crashes into the shelf of medical records, and he is sitting beside the wrecked shelf, both of his shoes are back on.
When Ed smashes into the filing shelves in the nurse's office, the files come out. When this happens, you can see that there is a person in a photo with the name of James. Jimmy's file and photograph are also briefly seen. The names Daniel, Raven, and Miller are also seen; these names referencing the producers of the show. Two other names seen are Marcy and Chris.
The name for a fear of needles is called Trypanophobia, as mentioned by Edd. The only ones who don't appear to have this fear are Edd, Jonny, and Plank.
Kevin called Eddy 'Florence Dorkendale' and Ed 'Nurse Twerpenstein.' These are references to Florence Nightingale and Dr. Frankenstein respectively.