The Headless Horseman Rides Again

While on a picnic the gang receives a letter from Mayor Mare to invite them to a costume party deep in the Everfree Forest in a scary old mansion which is haunted by the notorious Headless Horseman
== Script ==
(We open on the gang and their friends enjoying a picnic while Spike and Winona share a bone)
Snails:Like I'm glad we decided to have a picnic.
Rarity:So am I Snails.
(Adagio and Flash are sharing a sandwich and Bulk is sharing a sandwich with Rarity)
Aria:(Enjoying hotdogs)Mmm. These hotdogs are delicious.
Sonata:The same with these tacos.
Spike:This bone is good too.
Winona:Yeah Spike.
Applejack:Yup. Nuttin like some time off from mystery solvin to get ya in the mood for a picnic.
Rainbow Dash:Yeah, it's awesome.
Pinkie Pie:And these cupcakes are yummy too!
(Derpy comes in her mail carrier uniform)
Derpy:Hey guys you got a letter from the mayor.
Big Macintosh:So much for a relaxin day out. (To Bulk, Flash, Fluttershy, Pinkie Pie, Sunset, Rainbow Dash Applejack and the Dazzlings)Sorry y'all but duty calls.
(Twilight opens it and reads it)
Sci-Twi:It says. (Reads it)Dear Canterlot Mystery Solvers, you are invited by the Mayor of Canterlot City herself for a costume party at a mansion deep in the Everfree Forest, there will be food, games, and dancing and all sorts of fun. Sign Mayor Mare.
Sunset:It's not informing you guys about a mystery, it's inviting you to a party.
Pinkie Pie:Aw shucks! I wanted to go!
Sci-Twi:It says that our friends can come.
Pinkie Pie:Hooray!
Fluttershy:Um I don't think I want to go.
Rainbow Dash:Come on Fluttershy! It'll be fun!
Bulk:YEAH!!!!!! LET'S GO GUYS!!!!!!!!
Rarity:Really Bulk? That's not necessary.
Bulk:What?
Rarity:Yelling out loud when there are people around you.
Bulk:Oh sorry.
Big Macintosh:Then it's settled! We're goin to the party!
(They cheer and we cut to nighttime where we see the other van the gang have when bringing their friends along on mysteries it drives down the road)
Sci-Twi:It sure was nice of Mayor Mare to invite us to a party.
Rarity:Yes, but why out in the Everfree Forest of all places?
Pinkie Pie:Maybe it's because it's so spooky out here.
Snails:Like I'll say,
Spike:I'm kind of scared you guys.
Sonata:Me too Spike.
Aria:I'm getting that vibe. That feeling that the Headless Horseman is coming after us.
Fluttershy:The Headless Horseman?
Rainbow Dash:Relax Aria, it's probably your imagination. And besides, it could be a costumed guest.
Adagio:Yeah, listen to Rainbow. It could be somebody at the party.
Sci-Twi:After catching creeps in masks all week, this party could be a real break.
Pinkie Pie:Are we there yet?
Big Macintosh:Eyup. We're here Pinkie.
Rarity:My, that doesn't look like a good place for a party.
Bulk:I have to agree with Rarity on this. This place looks abandoned like nobody's been here in years.
Spike:This place is haunted.
Winona:Haunted?!
Spike:Not really haunted Winona. I only mean it's deserted.
Winona:Oh.
(They chat as evil laughter is heard)
Snails:Like what was that?!
Spike:I don't know, and I don't wanna know!
(They see a pumpkin headed man on a horse holding a sword)
Spike:The Headless Horseman!
Snails:I-I'm sure it's just a guest.
(The Headless Horseman comes at them)
Big Macintosh:Quick into the house! It's our only safe place!
(They run in and close the door)
Spike:That was close.
Aria:Now do you thin the Headless Horseman is real?
Adagio:I didn't believe it but now I do.
Spike:Yeah me too.
Bulk:What does that mean?
Big Macintosh:It means we've got a mystery.
Bulk:What do we do?
Sci-Twi:We do what we always do in this kind of situation.
Snails:Split up and look for clues. Come on Spike.
(They walk off)
Adagio:Flash and I will check out the basement.
Aria:Come on Sonata. Let's check the backyard.
Sci-Twi:This blueprint could be a clue. It's about building a new building on the land.
Big Macintosh:Alrighty. Let's split up like Twilight said.
(They walk off looking for clues)
(We cut to Aria and Sonata in the backyard looking around)
Aria:I don't know about you Sonata but I'm thirsty.
Sonata:Me too. I could use a coke.
Aria:Yeah a Cocacola would be good.
(They hear noise)
Aria:What the?
Sonata:That sounded like a horse.
(They turn to see the Headless Horseman)
Aria:It's it's it's....
Both:The Headless Horseman!
(They run away we cut to Sunset with Adagio and Flash in the basement)
Sunset:Flash, back when we were dating you always wanted me to go to your house with you.
Flash:And that never happened. You kept rejecting me.
Adagio:But I'm never gonna reject you Flash.
Sunset:Hey what's that on the table?
(Picks it up)
Adagio:It's an airplane ticket.
Flash:And this looks like a passport photo for some guy named....Mortimer Bae?
Adagio:I wonder what the others found?
(Cuts to the gang)
Sci-Twi:Haven't found a clue yet. 
Rarity:Hey what's that over there?
(Points to some stuff)
Big Macintosh:Looks like junk.
Sci-Twi:Hmmmm. (They go over)I beat who ever the Headless Horseman is, this is where he hangs out.
Big Macintosh:Hmmmm. All this stuff looks brand new.
Sci-Twi:Hey look at this. It's an old movie projector.
Big Macintosh:Somebody must be outa their minds to watch movies out here.
Sci-Twi:And there's another clue right there. It's a sword and a pumpkin head.
Rarity:And here's a whistle for only horses to hear.
Big Macintosh:This cape here could be a clue. And it's not mine. And looky there. Black paint.
Rarity:And what would a headless horseman want with a sowing kit?
Sci-Twi:You mean what would a headless horseman need a sowing kit.
Rarity:Oh.
Big Macintosh:Maybe whoever it is used that sowing machine to make the costume.
Rarity:And look at this. A copy of The Legend Of Sleepy Hollow.
Sci-Twi:And this looks like an intrusion manual like building a horse, paint it black, paint the eyes red, and put a whistle on it.
Big Macintosh:That looks like an instruction manual on how to make a ghost horse.
Sci-Twi:Hmmm.