Need help with coming up with ideas for an encounter [closed]

TLDR: I’m looking for suggestions and ideas to meet expectations of my players. I run out of ideas for a possible encounter with some deep dwellers.

Hi, i’m runnig a 5e game, it is a mix of the SKT adventure with an addition of homebrow story elements, it does not take place on the Sword Coast, but around Vaasa, Thar and the likes.

My party has recently arrived in a minnig town inhabiteted mainly by gnomes and dwarves. The town lies above many Underdark entrances. The ones that are known are heavily guared by the town guards. Of course most of them are guarded by the deep dwellers, which given the localization of the town would mostly be duergars or svirfneblin. The underground part of the town has been closed due to arrvival of an unexpected fugitive.

The party doesn’t know it yet, but it is a half elven woman who has almost miraciulsly escaped from a mind flayer colony, which lies somewhere below the town within 25-35 miles. The mind flayer colony has been attacked by a rouge powerfull mind flayer (and its followers), which is on a good path to becoming an illithilich in the future. It’s attack was an atempt to kill the elder brain of the colony, which the rogue one came from. The attact has shaken the colony and given a chance mind flayers’ prisoners to escape (one of them is the half elven woman mentioned earlier).

I described my players that the underground part of the town has been closed and that the guards have taken precautions for the possible arrival of pursuit after the half elven woman. It looks like my players are now expecting some big and epic encounter and I am not sure what to do. They don’t know about the mind flayers, but I think that the illithids wouldn’t pursue after a mere prisoner.