Well, firstly I must apologize for starting this thread before an unanticipated weekend away from technology. Secondly I must say I am overwhelmed by your outpouring of good ideas.
I will start near the end with a thoughtful post that colored my re-reading of each idea. masterofm: I like your thoughts. I take from that the idea that the conjurer should go somewhere remote and alone and do nothing to put down her spirit if it should go free. The spirit may be merciful when it sees no threat. We can just look back as far as Deus to see what a powerful being does when it feels untrusted. Perhaps one task spirit with first aid would be left alone to stabilize and treat the dying conjurer, or perhaps she should die in her folly and allow the Force 12 spirit to return to its astral home to play Texas Hold 'em. On the other hand, a Logic 12, Intuition 12 being must surely understand why a weak being would take precautions when begging from it the services that only binding can produce. Any little mortal had damn well better fear it! After all, the book does describe spirits as being quite vengeful when going free in such circumstances. Perhaps we should not trust in the good graces of the mighty being after all. None-the-less I will keep in mind the way the relationship between conjurer and spirit could be tainted by our precautions.
I see 4 general ideas coming from the community. I will address them in this order: 1) Conjure it from inside a bomb. 2) Bad-ass adept. 3) Bad-ass caster. 4) Big-ass gun/stick-n-shock
1) Put the F12 lodge inside a bunker coated with explosives on the inside.
While at first I liked this idea despite the cost of building the large bunker, it has several problems. The one of greatest concern to our dying conjurer is escaping the enclosure before it goes boom. Several bound spirits engaging the F12 as proposed by Adarael might slow it down. Powerful mana barriers and/or wards especially of the offensive variety (thank you Rasumichin) might also help greatly. Unfortunately, our being thrives with no physical presence. There is no way to get our conjurer out before the super-genius decides it should disappear into the astral. God help us if it spends its time busting through the wards/barriers and rests up before seeking justice. After reading masterofm's thoughts, I also decided this would create the worst working relationship even in the event of a successful binding. Sorry, but this one is declined.
A subset of this one is the conjure-into-a-deep-hole-through-fiberoptics idea. Our
very evil gm has decided that this won't work.
2) Bad-ass adept.
We currently have no-one on the team capable of going toe-to-toe with a Force 12 spirit of anything. Our fixer is a fairly well connected guy, but I'm not sure we can afford to pay a world-class combatant to risk death even if we could find one. Our conjurer is a little ahead of her team in this effort. I will keep looking.
3) Bad-ass spells.
This one could work. A little edge is not too much to ask a hired spell slinger nor teammate for a 3 second job--especially one that may or may not even be needed. Unfortunately the spirit has edge too. Lots of it as noted by De Badd Ass. Probably more of it than everyone put together unless we hire lots of spell slingers. This also limits us to spirits without Magical Guard. If we get a spellslinger that can punch through 12 conterspelling dice
and edge we're left with the "I'm not sure we can afford to pay a world-class combatant to risk death even if we could find one" problem. This can be helped with aid-sorcery services as The Jopp mentioned (indirectly), but I fear it won't be enough.
4) Big-ass gun/stick-n-shock
These ones that at first looked least likely and least useful will probably be the ones I back. I haven't fully decided between one big gun that depends on surprise so the F12 doesn't dodge and many many stick-n-shock guns that whittle down its dodge. Unfortunately it may take a ton of shots to whittle down a reaction of 12 and edge of 12. All this before it gets a chance to go astral. I think the mighty mana static spell is a wonderful addition to either one of these strategies.
Now, some tangents. While there are several ideas to weaken the spirit, I stuck with mana-static. Running away is very problematic with a being that can pop into existence inside your car. A high background count that is close enough to escape into but far enough away that it doesn't foul the conjuring site might be hard to find. Unless it was high background from happy happy joy joy stuff I would also fear what kind of spirit we would get.
Similarly there is conjuring within a background count. While this was not suggested it might be a good way to limit drain. (Depending on the GM's ruling of drain. Is it actual Force x 2 or modified Force x 2 that it rolls?) Unfortunately I will now shy away from this due to masterofm's cautions about the spirits attitude. We do not want a monkey's paw situation with our big genie.
FAB III: I need to re-read (and will do this in the morning) but doesn't FAB III split when it gets around Force 6? I believe our beast could engage this stuff in astral combat and destroy it. I think it would survive the FAB's attacks. In the end it's no more than a offensive ward.
Burning Edge: Our bastard GM has made a very limiting but agreed upon ruling that burning edge provides 4 automatic successes and may be stacked with spending edge. This may not be enough to live through an unlucky roll. Burning edge is expensive (in karma) and I'm not sure how you'd write that into a contract for hired help. It's quite a lot to ask of your teammates. Even the conjurer wants to avoid it if she can. (She's a bit karma hungry. Must be saving up for an ally.)
Personal responses:
Riverbane mentioned a clever strategy of binding it 12 hours and 2 seconds before sundown/sunup. While I like this, my understanding is that the binding can be successful, but if the mage gets knocked unconscious, it goes free. It doesn't have to go home when the sun breaks the horizon anymore.
Stahlseele: Unfortunately spirits only add their force to physical attributes. It is not useful for conjuring nor drain, and I don't want to put our conjurer in the position of having to withstand area effect attacks even with a greatly boosted body.
apollo124: I'm afraid we might not have time to die on a RATING 12 astral quest what with the beast clawing and tearing at our unconscious bodies. As for raising magic to 12? Our conjurer is impatient. (Though Rasumichin's suggestion of the adrenalin pump would help immensely in that case).
Awards:
While many people had wonderful and helpful advice for surviving the drain, that was not the subject of this topic. I can give no awards for those suggestions.
Rasumichin: You have been disqualified for using the false plural "boni." Sorry.
Coldan: You get an award for speedily suggesting mana static + sniper. Simple. Elegant. No massive explosions.
Sunnyside: Your idea of drones with stick-n-shock wins the lowest skill award. Drones have no skills per se. Quite the welcoming committee.
Ryu: I think your one big
50,000 gun might be cheaper than all the drones we'd need for something with that much reaction and edge. It's all good if we can give it to a teammate too.
masterofm: bonus award for your thoughtful step back from the whole process. Do-nothing may be the best thing.
Honorable mentions:
Heath Robinson for the biggest boom.
Jaid for a sound understanding of the mechanics.