Now it's not impossible for one to open a door without a doorknob, perhaps the door is an automatic door, or one of those sliding porch doors where if you press your hands really hard against the screen then slide it to the left/right you can watch it slowly inch along as you breath various curses to the sky, or maybe if you're lucky it's a poorly constructed door and even when it had a doorknob you could just knock it open with a swift kick of triumph. Of course if it happens to not be any of those kind of doors, and the door happens to be locked with one of those annoying separate latch thingys and the doorknob falls off than you better get a hammer, dynamite, and/or laser shark and carefully break down the door.
The Brothers, whom one happened to wield a hammer part time, were not thinking about door problems, they were just catching their breath, panting hard as the eldest held a three tickets in claw "...We made it, we had to set the Kart on fire but we made it"
"Hey that wasn't my fault this time, aight, it was just in poor shape" Janis complained, assuming his brother was referring to him when it came fire
"Whoa dude I think Kurt bro was just talking about the engine giving out or something"
"Yeah yeah I know, just fire is sorta my trigger"
"It is bro?"
"...Nah, I guess not"
"Guys take your tickets, here comes the train" Kurt handed his brothers said tickets, the loud sound of the train coming almost drowning out the sound of his voice.
"Trains are so cool..." Jack had a moment to say as the train pulled to a stop, but stopped his typical jive as even he could appreciate a moment of silence before the next of their journey would begin. Together all three brothers waited… and waited… four seconds of waiting.
Any moment now the doors were going to open their journey would begin… any moment now…
"Um… this is the right train, ri-" Janis couldn't finish his sentence as he caught a door in the face as it was kicked out sending the fire wielding, flower loving koopa to his fanny "...ow…"
On the other end of the door hopped out a small toad and his mother "You be safe now! You tell em that Ice Cold Cindy sent ya, you behave now Frog darling" a voice from behind the happy toads called out, one very familiar to the brothers, one they couldn't see the owner to, till the toads waved goodbye happily and with their bit of luggage made their way to the nearby Hotel, which surprisingly Bowser had quite the business in.
When the toads had finally walked off and the brothers quickly signed autographs for the younger one they got a chance to see whom the voice belonged too, which was now barking orders "You, yeah you! Tell all the passengers to stay in their booths, and you! Check all the doors again, I want them left open!"
"...Cindy?" all three of them raised an eyebrow in unison
"What, can't you see I'm busy her-" she turned around to see who was actually talking to her "...Boys!" she jumped down hugged them and quickly dragged them into the train slamming the broken door shut "What are you chuckle heads up to!" her happy demour snapping with her scowl "I had to come all this way to get you lunk heads out of trouble and I get caught up in train shinagines!"
All three brothers looked at each other, gulped and quickly passed the explanation to Kurt "Um, well I guess you saw the news right?..."
"You bet your hammer flinging butt I did, I can't keep coming back to get you boys out of trouble so you're going to tell me what's going on right now or so help me I'll freeze all of you and drag your cold fannies straight to Bowser."
"Whoa hey chill ou-" Jack was cut himself off for once catching his cousins gaze, fortunately Kurt came to his aid
"Look, we sorted it with his Majesty, and we've been sent on a mission to kidnap Princess Doofy." he said with confidence
"Daisy!"
"Princess Doorknob?, What?..." Cindy despite hearing both an incorrect name and the correct name for the Princess in question got it wrong herself and was most certainly confused at the topic
"Daisy! DaisyDaisyDaisy!" Janis was hopping made at this point "Her name is Daisy, like to flower!...ugh" he heaved a heavy sigh "And yeah, apparently the King wants us to kidnap her, so we were taking a train there."
Cindy looked at her family for a brief moment and burst out laughing "HAHAHAHAHAHAhahahahaha...hahahaha… Oh you're serious?... Well you're in luck boys, Old Cindy is pulling herself out of retirement."
"Wait what? Cindy you can't be serious, you can't help us kidnap a princess?" Kurt for some reason objected, even though he of all of them was the least enthusiastic of the whole venture
She laughed though "Oh no, you're going to be helping me figure out what's going on with all the doorknobs on this train- Hey nervous Toad!"
"...My names Frank…" The toad whom had the misfortune of being the first one to come contact stammered
"Alright Frank, get this train moving again pronto, I don't want that doorknob thief to get away"
"Oh-oh, ok…" the toad nodded and ran off leaving the Koopa's alone
"Alright boys we got a mystery to solve."
"Wait what?..." Jack was so lost, something about doors… you go through those right?
"Well I only need to know is when we split up and search for clues?" Janis chuckled "But seriously what's going on?..."
"Come on Boys I'll explain on the way" she grouped them together dragging them further into the train as it lurched forward, slowly out of the World know as eight.