This is almost a lore question, but it's related to mission design, so I'm putting it here.
So, I'm going to have a mission (or two missions, rather) wherein our heroes, comprising the HLD Apocalypse and her battlegroup, attempt to escape a system while being pursued by Shivans. The system is connected to the next by a Knossos portal. This is set prior to FS2, and so the Apocalypse had no prior knowledge of such devices.
The plan for the mission was this: the battlegroup heads through the portal with the Shivans right behind them. On the other side, the Apocalypse opens fire on the device, while the fighters and bombers hold off the Shivans coming through the portal until it's been destroyed. The problem is this: in all known examples, Knossos devices exist only on one side of a node, rather than there being a portal on each end.
Now, there are three potential solutions.
1. Place only one portal, at the destination. The problem with this answer is that this would require the Apocalypse battlegroup to go through an ordinary subspace node with no plan. Then they would come out the other side, see the portal, and somehow immediately come to the decision to destroy it. This is awkward and implausible, but more importantly, it cuts out the planning phase of the operation, and reduces the opportunities to present the Apocalypse battlegroup as competent and forward-thinking. Although admittedly, genocidal apocalyptic cults aren't typically known for those qualities. (Another problem is that these Knossi are supposed to be closed until the Apocalypse arrives, which is why there aren't Shivans on the other side. Unless the Apocalypse can somehow activate the portal from inside subspace, this wouldn't make any sense.)
2. Place only one portal, in the system they're leaving. This would require the battlegroup to do something like planting a timed explosive on the portal to destroy it after they've gone through, and it would also pretty much destroy the original gameplay conceit. Oh, and it would result in an even more Forced-Entry-like experience.
1. Just have two portals. This is hardly farfetched, since Knossi are deployed to stabilize jumpnodes. It's not like you couldn't have two nodes that were both unstable. This seems to be the best solution, but there's an issue with a disconnect between the characters and the player. The characters, not being familiar with Knossi, might easily assume that there will be a second portal on the other side. But the player will know that there usually isn't, and will expect the characters to be wrong. And there's no opportunity for an explanation when they turn out to be correct anyway, since the characters have no reason to believe this was unlikely.
What I'm thinking of doing is this: have the characters discover the Knossos, scan it, and figure out that it was created to stabilize the node. They're also able to determine that the exit point of the subspace corridor is giving off similar readings, so there's probably a portal on the other side that they can destroy.
I think I just answered my own question, but anyway. Thoughts?