Any ideas for an Escape and Recon mission?

My level 8 Party infiltrated the base of the evil cultists by posing as cultists themselfs. 

Their main goal is to find a way out of the base camp without being spotted, as they are heavily outnumbered. They cant take the same way they took in (astral sea shannanigans).

As this camp will also be the place where the final battle of the story arc will happen, i want to give the party a chance to do some recon to gather information that will later be helpful.

So now i come to you, the great hive mind of dungenomasters, to ask for some mechanics or ideas on how to fill the cultist camp:
how can i make exploring interesting? what information could they find? how do i seed said information? how can i give the impression that time is ticking? I always read about "failing forward" if the players fail a check, but how do i implement that?

You probably need 3 separate locations of sleeping quarters. The common area for the majority, a separate more high end for the upper management/leaders/officers.  And one for the the actual leader.

A HQ type building for the admin and actual leadership meetings/offices.  You need the place of worship.  You need a place for the organization to eat/cook.   Probably some sort of physical training center.  A school (academic) type training center.  A place to keep offenders like a jail.

The places can be combined in any way yo want, there can be tunnels connecting one section/building from another. Or this can be underground and it is all caves/tunnels.  Or just a mix.  Depending were you want it located.

You can have some sections free for a cultist to wander around in and some sections that need certain credentials.  Those places might have some sort of guards that are both fixed and roaming.

Never heard of  "failing forward", what does that even mean?

Have them make checks and have some close moments (like the gong goes for dinner after the guard looks in the room they are in), timetable of guard rotation, desks with papers and notebooks, sun setting, dinner, new rotation of guards. If they fail a check they make a noise and some guards come closer chatting revealing information 

how can i give the impression that time is ticking?

The most obvious is to have in the center or at the place of worship, a giant clock with the days up like a calendar.  That clock is ticking backward and many of the cultists know what it means, but many "recent" ones do not.

A more subtle way is to do it magically/telepathically.  The people who hired the party keep sending them a countdown.  It is either in there heads they hear it or a visual pops up (then disappears) in front of them.  Have them all make a perception check then give them the countdown, but occasionally have a perception check mean something totally different like a trap the cultist sent/created.

 

Never heard of  "failing forward", what does that even mean?

"failing forward in the sense that if my players fail a check, their mission is not immediatly failed and not all cultists come to swarm them. rather, the infiltration still goes on, but new obstacles are added because they failed a check