To me, most of the "mechanics" of mission building are retrospective. i.e., they tell you more "what you get for what you did" than tell you how to build it. (i.e., the "step 5" of the outline on page 426.
But if you haven't yet, I'd recommend you take a look at some of the missions in the free download area as examples:
http://www.crafty-games.com/downloads (skip down to missions under Spycraft 2.0)
To me (and sorry if this overlaps overmuch with the previously mentioned outline), the steps of building a mission are:
1) Premise: Something bad has happened or will happen and the players must act, out of duty or necessity. Decide what this is.
The premise can be multi-layered. E.G., an informant has information and must be extracted or protected. But the informant's intel might lead to a second thing the agents must do, e.g., stop the weapon from being stolen, the virus from being distributed, the president from being assassinated, etc.
If you have a specific agency that directs the action for the players, that might dictate what sort of things they try to stop. Some actual examples from games I have run:
- Institute for Policy Studies - An organization dedicated to dealing with corruption in other US agencies. Their missions either deal with corruption/moles in US government agencies, or missions that can't be done by other agencies because they might be or have shown to have been compromised by corruption.
- FLASHPOINT - Deals with immediate threats to national security that traditional agency bureaucracies are too slow to react to (terrorist threats, etc.) This was my excuse to make a multi-agency CTU-like task force for a 24 style game.
- Strategic Research Consortium - This private (but well funded and connected) organization is concerned with controlling technologies. On the surface, they help with disarmament (chasing down nuclear, chemical, and biological weapons) and controlling the spread of other weapon related technologies, but their private agenda has agents secretly dealing with more subtle technological threats, e.g., corporations that use technology to influence markets and behavior, proliferation of technology that could lead to an AI singularity, etc.)
Having a premise like these can help the missions write themselves.
2) Opposition: Someone will act to stop the players. Decide who.
This can be your typical villainous organization or opposed nation military or intelligence agencies. Or this can be legitimate security forces that aren't "in the know". Again, multi-layer can work here too. An organization might be infiltrated, there might be rival agencies that interfere with your efforts against the main bad guy, or neutral mercenaries, opportunists, and foils might have their own motives.
The Spycraft 1.0 book Mastermind is a nice idea soup for brainstorming this sort of thing.
3) Create 2-4 scenes
This is where I start to step into the structure in the book.
Usually, a different scene means a different location, though a single scene may span multiple smaller locations, or 2 scenes may be in the same location but with a situation change.
The book uses "objectives". Normally, you'll make 2 objectives to a scene. Think about it... if each scene is a different location, an objective is the reason you are going there, and what you hope to do there.
Decide what the players must do, and how the opposition presents itself, and any complications.
If the scene seems too easy, add a complication. For example, you may have a bad guy who has a thumb drive with some important data on it. If you have a team of bruisers, this might seem straightforward: Find the guy, beat him up, and take the thumb drive.
So, why is this hard? This is your chance to add objectives and complications. Look at each task I've set out above and think of why this might be complicated. Look at the objective tables on pages 431-433 if you need ideas.
For example, breaking this up:
Find the guy: is he hard to find? Is he disguised? Perhaps a search is required? Perhaps he's somewhere hard to get, like a secured building or a prison. Or a remote desert base.
Beat Him Up: Is he hard to beat up? Does he have an entourage?
Or better yet, is there are reason NOT to beat him up? For example, will he destroy the thumb drive if attacked? Will the fact someone else is after the data alert him or his allies to a future operation? Will it offend people who are supposed to be your agency's allies?
Take the thumb drive: If you were supposed to take it without him knowing, you may need some sort of ruse of sleight of hand. Or perhaps there are extreme measures to protect it. Does a bomb go off if it leaves his person? Is it surgically implanted in him... do you need to kidnap him? Or manufacture a reason to cart him off in an ambulance.
Once you have selected the objectives for each scene, that tells you the base award for the objectives and any complications.
One final trick to picking objectives:
WRITE THE OBJECTIVES TO THE AGENTS.
Go through the mission and pick out 1 or 2 things each agent is good at and put it in as an objective. You have someone great at computers... then at some point, require a computer to be hacked.
Lots of soldiers and martial artists? Make sure there's a good raid or fight scene.
A sleuth or other master of investigation? Try something that takes canvassing or a manhunt.
An intruder or other character with maxed out security and sneak? There'd better be a building to break in to.
And so on.
Go down the skill list and the class list of your player and match objectives to players.
4) Design your opposition, and derive their XP.
Samples from the adventures and crafty products are good for this. I also recommend Meadicus's NPC builder:
http://www.meadicus.plus.com/craftygames/npc-builder/5) You're pretty much done. You can split your awards up as the Living Spycraft missions do if you wish. I just eyeball this is the players didn't do everything they are supposed to.
When the mission is run:
Determine the threat level (total levels divided by 5). Remember you can tweak to taste.
Add up xp from objectives, npcs, and complications, and action dice*. Multiply by threat level to get the final xp award.
(* - I personally find tracking action dice XP to be a task. I'd recommend giving players a flat award like assuming everyone got 4 (i.e., 100 xp.))