Trying running my first Session coming up, looking for ideas

[GigaGuess]

So I have the gist figured out:

Group is tapped to go to an abandoned lab, to find out why townsfolk are vanishing, and aberrations are appearing in the vicinity, root out the problem and solve it.

However, I then tapped each player, giving them a twist: they are a clone made in the facility. They have the memories of their prime version, but only enough knowledge of the lab to know that they're:
a.) In fact a clone, and
b.) Their prime version is still trapped in the lab, so they have a drive to go to said person, leaving the why to them...save them, replace them fully, etc.

Also, I established that this is a group of strangers they are working with, and as such, will likely not to realize they're a creation of the lab they're storming, for fear of being branded a mole, and either being abandoned, or turned on outright. Sworn to secrecy, etc. etc.

So where I'm at is trying to plan out "Make the players sweat" moments, over being "found out." Two I have off the top of my head are:

A small cluster of guards seeming genuinely surprised to see the group in general, sputtering "Y-YOU?! Get them!!!"

BBEG commenting that "I suppose you think you're pretty clever..." talking to no one in particular, then offering "you and your friends" the opportunity to become new Primes to begin cloning again.

Any other ideas?

[FoxWolFrostFire]

A good way to do it is add an NPC or two which also have clones which the WHOLE group clearly see that there are clones from the lab which are in the current group. Making every one starting to point fingers at each other. Could be a good use of bluff checking.