Yup. The party is level 11 Gestalt (Human Monk/Druid, Human Fighter/Monk, Elf Wizard/Ranger (Ranged), and Aasimar (Oracle (Life)/Bard (Archivist)).
The scenario (as I have it planned) is that the PC's will be informed that a train is heading to the capital city, which has had a magical bomb (250d6 Sonic damage) loaded and will erupt when it arrives in the city's station. The PC's are far away from this location, and, as they will be given the train's engine number, will probably use a magic item they acquired in the past to Greater Teleport onto the train.
The train, to thwart robbers, has been outfitted with a Teleport Trap spell, which will shunt the PC's to the back of the train, into the "brig". This will be purposefully easy to break out of, though this, and all other cars will have Antimagic Fields active after the Teleport Trap is activated. The Antimagic Field spells are coming from devices hidden above a ceiling panel in each car, and can be deactivated one by one. The train is a "luxury train", and its cars are linked in a way that there is no way to climb to the top of the cars just by leaving one of the cars. The PC's could still get to the top by breaking open a wall and flying out and up, though. The advantage of this is that they would bypass most of the encounters.
I would hope that they wouldn't want to risk just derailing the train, as they don't know the bomb's radius/output. The idea is that they need to enter the engine car to manually stop the train, or retrieve the bomb. Most of the encounters on the train are the train's own security measures, which the terrorists have turned in their favor. One car has three Glass Golems. Upon activating (recognizing the PC's as a threat), a daylight spell activates in the car (procing three separate Fort saves to avoid being Dazzled). Another car has two Stone Golems. When one Golem is destroyed, a targeted Transmute Flesh to Stone spell will heal the remaining one.
I'm looking for other encounters like these; security measures that the train could already have had (that won't seem ham handed when used against the PC's). Keep in mind that passengers - upon buying their tickets - are given special coins that broadcast a signal to the Golems, labeling them as a non-threat. Other measures like this would have been made with other encounters to keep passengers safe. Any ideas would be appreciated, especially countermeasures against running up the length of the train from the top!
Well, threatening the passengers seems like it would be one of the more exciting things you can do here. Anyway, at a glance, a few things come to mind, whether they work for your group well, it just depends:
1) The classic disconnect the cars trick. They now have to get over to the other side. Granted, this should be a relatively easy thing for them by this level, but with the teleport trap it may make things interesting, particularly if they forgot about it. It should be a fun non-combat encounter.
2) Combat in the dining car, full of guests. This is much better if your PCs care about collateral damage. If they don't, well it will still be fun, just less so.
3) Forcecage traps. This sounds appropriate to how advanced the train is and can be all kinds of awesome.
If they do fly over the trains, remember the trains have antimagic fields. These could be going out 20 feet above, to the side, around. This will make landing fun - imagine falling 20 feet onto a train going 45 miles an hour, good chance you will be flung off, caught between cars, etc.
Those are cool ideas. The Teleport Trap no longer functions after the Antimagic Spells are erected, or else that would indeed become quite an added challenge. The fact that passengers (and expensive train property) will also be in danger is something I am well aware of. I am looking for other measures taken specifically by the train company meant to keep the train robber-free, though. The cars detaching is a step in the right direction.
If the train goes faster than flying characters, flying will be useless.
Wall spells of any kind may block access very efficiently.
The bomb trigger may be located inside an extremely mobile automaton, designed to evade pursuers lacking correct identification.
Regards,
Ruemere
That's a good point about the flying speed. I did some quick math; 60'/round is equivalent to about 6.8 mph, right? so even taking a double move would be slower than the train (which is going no slower than 30 mph.