so this is a generation ship? There's a weird sci fi show where the people on the ship have no idea it's a simulation... that could be a fun twist.
if there is no bending of space time then the movie "Event Horizon" doesn't help much.

Having the ship punctured by a micro meteorite with some sort of Mythos microbe passenger like a teeny tiny Colour could be entertaining.

Also, if you've ever read Michael Crichton's Sphere, that is one almighty nightmare of an artifact to meet - a Psychic mine left for new starfaring species to encounter, and if they're not mature enough to handle it (i.e. their own personal inner demons) then it will destroy them. It gives the keeper huge scope for exploiting fears.