Some excellent ideas there. I appologize for the slow reply, college has been taking it's toll. Impossible geometry and weird gravitation has already featured prominently in the campaign so tying back to that and increasing the weirdness further would be a nice throwback to earlier events. In particular a race called the Stryxis built their ships in 4 dimensions. (The players had to navigate a hypercube at one point to get to the Stryxis ships reactor core. It got so complicated I lost myself and a player had to correct me at one point.) A ship in a place called Processional of the Damned also had strange overlaps in time (They saw and interacted indirectly with the players own father, 20 years ago when she was just a child and actually saved his life. This actually resulted in a paradox as in the original timeline he had died) Weird gravity has also featured. Fractals is a good way of showing complexity and just how alien the superintelligence is. (Who mostly wanted to be left alone after the rest of the galaxy went to hell in some quasi medieval society.) I like the idea of things that look like just a dot spearing through them or monofilament wire. Disassembling walls is also an insidious danger. Or perhaps even worse, things that add to them. Im not certain what it's goals are right now. Some parts might be curious about the strangers. It was wounded previously during a civil war where parts of it rebelled and wrecked a great deal of it's systems and left several weapons of war behind though dormant. Perhaps part of it is isolated from others? On the outside a force of the Yu'Vath, which is the deranged faction that originally rebelled, is assaulting the Sphere and trying to get in. Perhaps it wants to destroy them or reintegrate them? Playing around with nanomachines that recreate memories and former events in the story is a great idea. Gives an opportunity to go back to previous events in the campaign. Perhaps I could even have the players play out the roles of other characters in the simulation, such as the Rogue Trader Sarvus Trask that is the long lost father of the players leader. (And who was captured by the Sphere and had his body and soul, since it is soft sci fi, separated from his mind forcefully.) 2001 A Space Odyssey also comes to mind, familiar places. Something like their own bedroom with subtle details telling it is wrong. Like you said with the childhood memories. Or an entirely white room with a single object like a bed they recognice as their own. Im wondering where I shall take this whole thing. The sphere has the power to change the fate of the entire sector with it's immensely advanced technology. Perhaps a multiple choice ending like the Deus Ex games? One thing is certain, the technology is beyond the imperium and would be extremely dangerous if they just take and try to use it outright but parts of it might be understood on at least a practical level. (But hardly a theoretical one.) If they poke around too much it might decide to do something they might not want, like take apart some planet they would like intact, transport entire populations somewhere else, change minds, make othrers ascend to become warp creatures (Which happened to the breakout faction, they on purpose made themselves into Warp Beings but failed because they were attacke during the process and became a fractured warp god called The Many. One npc wants to ascend the entire imperium using the same tech but hopefully successfully this time. Unfortunately he might be manipulated by an outside force.) Even the Eldar fear the Sphere and has previously deemed to leave it in peace.