As the sprinting man dashed down the Sunnydale sidewalk, closely pursued by three demons calling out loving endearments during their chase after the target for tonight with those superlatively tight buns in his absolutely darling costume, several miles overhead in the night sky above the California city, fingers that could crush lumps of coal into diamonds hastily clapped themselves over a pair of Kryptonian lips, just in time to prevent a gale of laughter from escaping that would've surely shattered windows throughout the entire town.
The mental passenger inside Superman's mind had no such inhibitions. Xander Harris was flat on his non-physical back, clutching at his ribs while roaring with hilarity at the top of his unreal lungs, as he hugely enjoyed his sharing of Clark Kent's observing with his telescopic vision the supremely absurd event taking place down there. As both snickering individuals in their single body continued their gratifying scrutiny, Xander eventually giggled, *Oh, where's Jimmy Olsen with his ever-present camera when you really need him?*
Just barely keeping his own snorts of mirth under control, the superhero with a very famous costume and floating in mid-air, his red cape slowly flapping in the night breeze, now managed to utter, in an increasingly serious tone, "Xander, as much fun as this is, I do have to return to my own life. So, it's time to go to that, er, guy's rescue-"
*Pleeeease! Just a few more minutes! I mean, it's not like you have anything else to do now!*
At that teenager's unreservedly heartfelt mental appeal, the corners of Superman's mouth lifted in a rare sardonic smile. Still, the Man of Steel admitted to himself, in a private corner of his own consciousness, that Xander had an actual point.
When the last son of Krypton had somehow been instantly conveyed from flying over Metropolis during a fine spring day into a small California city on Halloween night there, Superman had straightaway shifted into speedily existing a thousand times faster than normal, allowing time to pass more rapidly for himself than this occurred in the rest of the town's reality. Now that he had more than enough time to properly investigate just what had happened without being overtaken by events elsewhere, Superman started by interrogating the unexpected visitor in his own mind.
After resignedly working through Xander's fan-boy daze, Clark ("Yes, you can use my first name; just please stop gibbering, will you?") had spent a few more minutes in accelerated time, with less than a second occurring for the rest of Sunnydale, mulling over what he'd just learned from that awe-struck teen, and then Jonathan and Martha Kent's adopted child had confidently gone to work.
After traveling throughout all of Sunnydale at superspeed to identify and capture all those people who'd regrettably bought one of Ethan Rayne's costumes (Clark would never match Batman's detective prowess, but the Daily Planet reporter did have some experience in figuring things out. "Yes, Alfred is just as impressive as he's shown in the comics."), those unfortunate individuals were detained in comfortable, protective custody to keep them safe from harm, either from themselves or incurring this to the unchanged populace. Which included Xander's friends. During all of this, a fascinated Superman also encountered at first hand Sunnydale Syndrome when other costumed revelers in the city speedily forgot about tonight's events, and the hero started to wonder why he wasn't himself influenced by this.
An overjoyed Xander managed to tone down a bit his enthusiasm about everything, to then hesitantly suggest that since they were sharing the same consciousness and the Sunnydale native's memory wasn't affected, maybe this protection was also shared. After receiving an actual compliment from honkin' S*U*P*E*R*M*A*N over that excellent insight, Xander stopped hugging himself in his sheer delight, to again diffidently propose that, uh, maybe, the big guy might as well, if it wasn't too much trouble…
A very amused DC Comics character good-naturedly assured that young man, "I'm already planning this, Xander. It's a good thing the dimensional barriers here in this place are pretty weak, anyway, since I have to use this world's technology. Now, just relax, and enjoy it all."
Over the next few hours for them both, as a second or two passed for the rest of Sunnydale, an effective-enough Phantom Zone projector was built and used by Superman upon every single bellicose vampire, demon, and other unearthly creatures having any malevolent plans whatsoever for the normal humans of Sunnydale. As advised by the busy hero, Xander kept quiet and refrained from disturbing Superman at his work, save for one sole exception of those evildoers that were presently being sent as insubstantial spirits into another dimension, never to return or to affect events in Sunnydale ever again. Not wanting an actual temper tantrum inside his head, an exasperated Superman reluctantly did something that made a teenage boy much happier than he'd been for the last few weeks.
Spike really hated Halloween. Even if he hadn't already despised a holiday that had soddin' humans swank about like they were real monsters, the British vampire now totally loathed his current situation during this specific festival, that had gone from one second of peacefully working upon his latest plan to kill the Slayer, into the very next moment of one way or another incomprehensibly changing him into some type of ghost that had been stripped of every stitch of clothing except for his boxers, his head shaved absolutely bald, and a message drawn upside-down in indelible ink upon his bare tummy for Spike to easily read: WITH LOVE & KISSES FROM THE SCOOBY GANG.