Carl West has been a tornado chaser all his life.  He is one of the most respected men studying the phenomena, but now what he is observing on the recordings he took of a recent storm totally perplexes him!  He picks up his phone and calls his associate Ray Standard.
"Ray," he remarks, "will you come in here for a minute?  Something really weird on the Doppler recordings from the Raytown storm!"
A few minutes later Standard came in.  "What you got?" he asked, in his deep southern drawl.  Carl played the recording.  "Here," he remarked, "just as the storm forms.  See this?  Three objects appear at the top of the super cell, appear to ride the down draft down almost to the ground, then shoot into the vortex, and spiral back up.  I've never in my life seen anything like this!  It's not debris."
"Sure as hell isn't!" his associate agreed.  "Debris doesn't come in from the top of a storm.  What in the hell is that?  It almost looks like it's something playing  in a category four tornado!  I've heard of people reporting seeing objects like this, but it's the first time I've ever witnessed any of 'em!  Let's call Greg here from the university.  Maybe he's seen something like this.  He looks at a lot more tapes than we do in his computer modeling."
West agreed. They put the tapes away and waited for their associate.  When he arrived he was rather amused at first, with his friends' description, but as he watched the recordings his amusement quickly disappeared.
"Ronston's tornado riders!" he remarked, "Damn!  I wish he'd lived to see this!  He got pictures of these back in the 50s, but they disappeared from his lab.  He swore they existed, but everybody laughed at him.  No one can laugh at this!  These images are so clear you can determine their size and mass.  Two of them are about six feet long, the other's about five.  And there's no question they're riding the vortexes!"
"What in the hell could they be?" the other two scientists asked.
"I haven't got the foggiest!"  their associate answered.  "But these recordings will prove they exist.  I'm going to make copies and take them to my lab, study them more."
West shrugged.  "You're welcome to them!" he remarked.  "But you're going to be the one writing the paper on this one.  I'm not touching it!"
They made the copy, decided to call it a night, and everybody headed home.  The next day when West opened his office he looked around, bewildered.  He knew where every single thing was in his office, though others would've thought the place was total chaos, and he knew things had been moved.  He checked everything, and everything appeared normal.  Then he looked closer at the tornado tape.  It looked like his tape, it looked like his handwriting, but it wasn't!
"Son of a bitch!" he muttered.  "He took the tape out and put it in the player.  The tornado was still there, in all its magnificence.  As far as anyone could tell, it was the original tape, but the riders were gone!  There was no trace of them!  "Son of a bitch!" West muttered again. He picked up his phone and called his university colleagues.  "You're not going to believe this!"  he remarked, "Somebody's been in my office. They've switched the tapes!  The riders are gone  from my copy!"
There was a deep sigh from the other end of the phone.  "I was just checking mine," his colleague answered, "I was going to bring in some other people to look at it.  Mine, too!  Apparently we've come across something that isn't supposed to be seen nobody's supposed to report.  I know I'm not going to!  If somebody's gone to this much trouble it's best to leave it alone!"
"Yeah!" West agreed, "Yeah!  See you later.""  He hung up the phone, took the video out, stared at it for a few moments and put it back in its place. "Son of a bitch!" he muttered again.  "What in the hell were they?  What in the hell were they?"