Starting In Media Res

[UmbraLux]

Looking at the title I wondered what could possibly be problematic about starting in media res...seeing this, I think I understand your concern. 

I'm still figuring that out.  But I do plan on having the entire route and attendant complications plotted out beforehand so I can spend my time and effort during the game on adjudicating what will undoubtedly be a chaotic batch of lunacy.  

This appears to go beyond starting in the middle of the action to scripting the action.  Not necessarily 'bad', but it does require more buy-in from the players than simply starting out with something going on.  You're asking the players to follow your script and avoid any choices which might lead away from or prevent access to any of the sites you plan the chase through.  I recommend telling them up front you'd like to script the beginning and ask them to play along with your script.  Let them know when they're off script and free to make other decisions.

As for locations I want to subject them to, more or less in order: (Scene Aspect: A Stern Chase Is A Long Chase)
An Icelandic glacier (complete with jumping off an ice cliff into the Nevernever portal before it closes)
A place in the fields of Winter.
St. Petersburg, Russia
A Goblin Market
A Bazaar (either the Khan Market or Chandri Chowk) in Dehli, India
A Nevernever jungle in Summer, inhabited by a plant that's a cross between kudzu, poison ivy and a venus fly trap.
The Phoenix Desert Botanical Garden
The Deserts Of The Crystal Pyramids
Either the Australian Outback near Uluru (Ayers Rock) or the Egyptian Sahara near Giza.
Then the capture and the "Um.... how are we going to get home?"

It does look like an interesting set of locations!  Even better, several have the potential to add complications if they're there for long. 

[bibliophile20]

Looking at the title I wondered what could possibly be problematic about starting in media res...seeing this, I think I understand your concern.  This appears to go beyond starting in the middle of the action to scripting the action.  Not necessarily 'bad', but it does require more buy-in from the players than simply starting out with something going on.  You're asking the players to follow your script and avoid any choices which might lead away from or prevent access to any of the sites you plan the chase through.  I recommend telling them up front you'd like to script the beginning and ask them to play along with your script.  Let them know when they're off script and free to make other decisions.

The "script" index cards are going to be my method of initial exposition, and I'm only going to have a very short script--if the master script is more than half a page long, I'm doing something wrong.  After that, the only thing plotted out are what events they will encounter along the route--and that's only plotted out so I don't have to come up with them on the fly, which would take time, effort and concentration away from the PCs.

(and one thing I'm going to do--to incentive myself, as well as the PCs--is put between each card a fate point chip; they get chips to spend on their chase without touching their normal refresh, and I'm encouraged to be brief)

It does look like an interesting set of locations!  Even better, several have the potential to add complications if they're there for long. 

  I will hopefully avoid stranding a PC anywhere where survival is a doubt... however, there are a few where an international incident is certainly possible fallout.  Of course, if anyone has any sufficiently entertaining suggestions, I'm more than open to hearing them (I'm not going to be running this scenario for at least a month, so I've got time)

[UmbraLux]

The "script" index cards are going to be my method of initial exposition...

It's not scripted because you're using note cards, it's scripted because you have "...the entire route and attendant complications plotted out beforehand..."  That's what I recommend seeking player agreement on. 

As for potentially entertaining complications, language and (mis)translation potential abounds.  You could add gardeners to some of the plant scenes.  You have a couple environments they may not be dressed for and the goblin market could be selling anything or even anyone. 

[bibliophile20]

It's not scripted because you're using note cards, it's scripted because you have "...the entire route and attendant complications plotted out beforehand..."  That's what I recommend seeking player agreement on. 

Ah.  I see what you mean.  Okay, my notes are going to look like this:

St. Petersburg, Russia
Finish Line for this segment: 8
Heavy Traffic; +2 difficulty to most Driving rolls; increase to difficulties factored in below.

Issues
Majorly Bad Potholes
Difficulty Of Great (+4) to avoid potholes and other cars entirely
Average to Good results in penalty to other actions such as Guns rolls.
Mediocre or below results in damage to car from hitting ALL the potholes at speed; apply "Bent Axle" or "Distended Tire" as appropriate. 

Lady Pushing Baby Carriage Across Road
Difficulty of Good to avoid
Roll of Fair to Average results in hitting the mother.
Roll of Mediocre or below results in hitting both.

Finish Line Reached: Warlock opens another Nevernever portal; Difficulty of Superb to shoulder other cars aside and prevent them from entering.  Great to Fair results in a few civilian cars going through the opening before it closes.  Average or below results in civilian cars going through the portal, which closes before the PCs pass through. 

So, while, yes, it's technically a script, for certain definitions of the word, to me, it's more notes on "where are we now?" and "uh-oh/oh... CRAP" possibilities decided out beforehand so I can focus on what's truly important--keeping up with the unpredictable antics of half-a-dozen college freshmen. 

[Ranma1558]

In media res is a great attention grabber, the most important part is to still have 3 acts to your adventure, the start of the adventure is obviously on act two, the rising conflict. The most important thing to do is fill act 1, the build up, preferably before you finish the first action sequence. You can handle this in a few ways:
Font load background dump: You tell what they did before hand. "You've been chasing person X for hours, finally you corner him in a parking garage where you both jacked two cars, the race is on." ect. This method is quick and easy but might leave your players feeling like they have little control of their characters.

Rear end background dump: You finish the action then give all the information about how they got here in one large dialog, you can incorporate what they said and did during the action into your narrative.

Time rewind: they finish the action, are about to interrogate the baddy or fall into a worse situation then you pull it back to the start of adventure and let them play themselves into the conflict. This is similar to how the Odyssey is told.

Small tastes of background: write note cards with bits of background pertaining to certain players "Joan you're ticked at Nathan for letting the warlock slip through your trap at the baseball field." "Frank, you lost your gun during the struggle with the demon he summoned." Give them to your players if they bring up a complimentary point or you want some more conversation rolling. The players "feed" each other background as you continue the action.

Leading question backdrop: My personal favorite method for this type of gaming, ask your players details about the background that keeps your narrative mostly unchanged. "Joan who's fault was it your trap for the warlock failed?"  "Frank, your gun is gone, how the hell did that happen?"
Maybe Frank's player suggests the demon on his own... suddenly its no longer a two man race you add in the warlocks demon coming up from the rear.... you get your players to play their characters, keep your story, and maybe add awesome things your players come up with you never thought of.

[Arcteryx]

Not that I've anything against a car chase, but... why wouldn't the warlock just hex any car they are in?

[bibliophile20]

Not that I've anything against a car chase, but... why wouldn't the warlock just hex any car they are in?

Rule of Cool?  Rule of Plot?  ...  He's driving a well-maintained, frequently maintained, high-quality piece of German engineering? ...  Maybe that's what finally enables the PCs to catch up with him--he pushes to hard and the engine quits on him. 

[admiralducksauce]

Well, it cuts both ways, right?  The warlock can intentionally hex the PCs' car, and the PCs can compel the warlock's High Concept to have him hex his own car.

I figure it'll be a scenario where the table either agrees that they want a car chase or it devolves into a foot chase quickly.  Or copious FP are spent buying off hex-related compels.

[bibliophile20]

Session for this is starting in half-an-hour.  I'll let you guys know how it goes.