WWTITAND?

Destroying the base is good operational security: the consortium will lose a spacecraft, some morphs, a research object and the chance to investigate the intruders (plus have to resleeve backups of the team), but TITAN outbreaks near Mars on metal-rich asteroids (especially if they could get access to a courier ship) are worse. Activate the nuke and let it (and the fuel of the courier) take care of the base. As a bonus, big antimatter detonations likely overpower small ones, so if the intruders have emergency farcasters they are unlikely to work (hence keeping possibly infected minds from spreading).

Second order considerations: if the intruders are not crazy TITAN cultists they have some operational goals. A likely set would be to get the computer, get some of its information and/or to deny it to others. Survival might or might not be relevant, as above. Threatening them with blowing everything up would force them to do something if they 1) want to get the computer, 2) need time to get the information (and transmit it somewhere) or 3) want to remain continuously alive. If they regard denying access as important or do not care about survival, threats might be counterproductive. The most likely response to threats would be to try to defuse them: moving the courier away, remotely locking the nuke and/or preventing the consortium from acting. This would be a trade-off between how much the intruders need to work on their own goals (and how quickly they can be achieved) and how bad it would be to be thwarted - by making the threat and monitoring the immediate reaction useful information can be gained and sent home, but the intruders must not get a chance to succeed in their work. Make the threat, observe the reaction, detonate everything prematurely.

If they were to start negotiating this would imply that either they are stalling for time (for an attack or for achieving their goals), need to avoid explosion (move something physically somewhere, maintain continuous life) or that they do not care to deny others the site after their work. All this in turn implies that their goals would be thwarted by an explosion. Hence, if they send a negotiator, blow things up.

The thing to look and hope for is internal dissension: are the intruders unified? If they are not, then there is a chance of getting useful information, possibly allies. Again, a threat of imminent destruction might shake something out of the woodwork. If they remain unified, then that is good intel but a reason to blow up the base. If they start to fight internally, then there is a slim chance of taking control - but it requires a credible threat.

Incidentally, it would be useful to boobytrap the courier ship just in case.

Logic dictates that soon something will be an expanding ball of plasma.

I know I'm the chancy type but I would just quarantine the area with warning transmitters, ring the asteroid with deaf killsats put a few really nice high magnification spy satellite with T-ray scanners around it and monitor the situation as a study of TITAN infestation procedure. Anything tries to leave: slam the asteroid and turn the courier into subatomic particles as soon as the engines warm up. But having an already isolated space with contained but activated exsurgents is too good of a opportunity not to be a voyeur about it.

However if the hammer has to come down it has to come down HARD!

But it makes for a damned fine adventure don't it?

I have to agree with the general consensus here. The team of scientists probably are best off setting the nuke that the pirates brought with them to go off. If they really want to shut it down? Set up the nuke so that it will trigger the antimatter containment of the courier ship engine to fail at the same time, resulting in an even bigger explosion.

Downside to this plan? The second team might not be able to get out in time, before the explosion goes off. Luckily, death is reversible. Let's hope that the Planetary Consortium set up some back-ups of the team, just in case.

Well, doesn't it also depend if the team knows its a Titan threat, Their orders may simply be find out what went wrong. Well they have one idea what went wrong (blaming the mishap on the intruders). They are clearly not strong enough to clean them up (without blowing the nuke), and has many reasons to report back.

Also Why blow up the evidence when a overkill option exist. If they think its imminent Titan threat I'm sure they are obligated to notify Planetarys Consortiums defensive systems. If only to prevent a second Fall.

If some goverment officials see a forest fire, do they try to do deal with the fire themselves or do they call the firedepartment?

I can see Second team decide to sabotage, commander or tow the pirates ship away, as well as their own ship to a "safe" observable distance & blockade the asteroid. While they also issue a alarm/mayday & call back home for further instructions + reinforcements . The Nuke & the culprits ship will be good leads to investigate the identity of the culprits.

Of course new orders may be to keep things quiet, blow up the space station, etc. In which command of a nuke, area control & blocking escape routes becomes a big plus.

I'm sure Planetary consortium probably has built a large untested fleet to defend against a second fall scenario, A fleet itching to test their destructive capabilities.