This synopsis is available for the use of private individuals, anyone wanting to make a profit off it should contact Lance Berg regarding some sort of reimbursement...The characters are recruited to do a job, but the job screws up and dumps them in the middle of a hijacking. They are on their own as to whether they try to stop the 'jack, go along, try to join, or take over (the last is what my players ended up doing...)
This mission is designed for a group which doesn't have a ship of their own. Other than that, it's fairly adaptable. It would really help when you are asking for this sort of thing if you could be more specific, although perhaps you are really looking for a campaign starter, and don't have any preconceived notions to work with.
1) Getting hired. Make up a job involving a covert government operation which needs deniable assets to perform a scouting mission. The characters are to board a luxury liner, travel several jumps down the line, then take over a very stealthy small craft being shipped on board, use it to travel to a moon of a separate planet in one of the liner's destination systems and do their mission, then return to another liner going the opposite way for pickup. This should be attractive to the characters on a variety of levels. The job itself pays well, which may be enough. It involves a weeks long cruise on a luxury liner, which is a nice fantasy. They can easily expect to jump ship and dump the mission at any point along the route; if you start them out down and out, stuck on a hellhole planet with no way off this itself could be sufficient. They might reasonably expect to get away with keeping the stealth craft...
2) Getting sent out. They meet their employers at a shipping terminal in the local port, before it opens for the day. There they find their contacts pulling open some large shipping crates. Inside are autodocs, and nearby are some smaller crates. They are instructed to put their luggage in the smaller boxes and affix labels off a sheet, then to get into the autodocs. Examining the sheets show stickers with a bogus passenger bio and address down the route past their destination. The autodocs seem perfectly functional, a model without 'glass port, all slick chrome exterior. Once someone gets in (and it turns out one of their contacts is going along, so he'll go first if that's what it takes) one of the party may notice that the "occupied" light and all the monitors seem to be malfunctioning, the 'doc shows condition nominal. Turns out that the group is being smuggled in low berth, using the autodoc freezer capability. These units are marked as being transshipped from a high tech planet, with plenty of routing detail available to anyone checking up on them; they are posted as replacements for emergency systems aboard the liner they are traveling on. This may confound those who were looking forward to the luxury ride or to jumping ship, if they figure out that they are going to be kept frozen the entire voyage (not every group of players will...) and your plot may even fall apart at this point. If you have set up sufficient back story, you may have the germ of a new plot line, in which the party tries to figure out what was really going on, or the employers try to eliminate the party as "knowing too much..."
3) Rude awakening. The autodocs open, releasing the PCs from freeze into an emergency bay, with lights blaring and an general order to go to lifestations running. Their contact knows nothing about this, it was not part of the plan. They were supposed to be awakened slightly before coming out of Jump space while everyone was in their quarters or at duty stations for the transition, make their way to the cargo bay, and pick up their things and get into the small craft, preparing to launch just after coming out into normal space. They seem to be where they were supposed to, in a large room full of other freezer bays. All the others seem to be occupied, though, and the alert system is cycling through a variety of languages announcing life support failure... All the berths except their own read full, if anyone takes a look.
4) Another Jolt. There are two exits from their chamber, taking the one they were supposed to leads them through a double lock (door, space, door door space door) into a corridor. The other door has large labels reading Crew Only. Oddly, although anyone familiar with the anti-hijack programming on shipboard knows how difficult it would be to get through it, and probably disregards it, they will open easily, to reveal a cramped small craft flight deck, unoccupied, view ports showing the roiling gray of hyper space. Too, characters who are interested can easily get full access to the ships computers through access points along the wall or so forth. A list of running software will not include an anti-hijack program... At any rate, hopefully the party will (perhaps with prodding from the NPC) get moving too quickly to get seriously involved. They have a tight schedule, after all, have to make it across the ship to their craft and ready to launch, which is going to happen at a specific time unless someone overrides it; less than half an hour form now... The message on the intercom will change to "transition eminent" warnings and then the group will go through jump transition, a very bad one. Their contact will go completely useless at this point, a victim of transition lapse. Shortly after this, the warning will go to "abandon ship, catastrophic drive failure eminent!" Hopefully the group will be through the locks by now, as there will be a shudder, and the lifeboat they were in (probably unawares) will launch, along with others along their corridor. At this point (although they don't know it) they and the hijackers are the only people on board the liner. If they stayed on the boat, the scenario is going to go differently of course, you are on your own here...
5) Now What? Here the party really takes control of its destiny. You'll need maps of the ship, locations and schedules of the hijackers, and so forth; but there is no knowing what they'll try. They may even manage to ignore things completely and make it to their craft, which is really there and set up for their mission. Since you'd rather they deal with the scenario you worked on, try to make sure they encounter at least one hijacker on the way... The idea here is to engender a "Die Hard" or "Under Siege" scenario. Have fun
6) What really happened. The "government" which hired the group was really an interplanetary corporation. They arranged through other disreputable contacts to have the anti-hijack program aboard the liner sabotaged, and for the experimental stealth craft being shipped to a government testing area to likewise be hijackable. Unfortunately, the agent they set up to actually insert the Anti-hijack disabler decided that this would be the perfect opportunity to take over the ship for himself. He brought aboard a number of confederates as passengers, and when the Anti-hijack routine shut off, they put in place the emergency alerts, planted false reports and readouts, and generally got the entire crew and all passengers into emergency freezer bays. Once the ship breaks out of jump, it launches all lifeboats and transmits a distress signal, with full (doctored) logs and telemetry indicating runaway drive failure, and consistent with what the occupants of the boats believe was happening... All the people in on the plot are listed as being on one of the boats, along with the purser who started everything. This boat floats nearby, drive apparently malfunctioning. In reality, the hijackers have loaded it with explosives and scrap pieces identifiable as being from the liner, including the "black box." They are busy ramping up the capacitors to jump as soon as they can. When able, they plan to dump more explosives, and have everything go off just as they jump. When authorities arrive, they should find debris, the hijackers all lost in the explosion, everyone else safe in their lifeboats headed for the main planet in the system. A very close investigation may eventually show insufficient mass/energy to account for the liner itself, but that could take months, if it happens at all.
7) Hijacker's plans. Part of a separatist movement, they plan to take their entire group on the liner along with colonization gear, and head out for a distant colonizable world, there to use the liner as their first home. This is a complex plan, with clandestine fueling stations, the pickup of the group, and all sort of other details which need to be worked out, if things ever get that far. Since the scenario revolves around the PCs and the hijacking itself, I've never had to go into too much detail as to what will actually happen, but it is important that you have some ready answers as to what the plan is, since the PCs may very well try to find out. Who knows, they might even decide to go along!