Sasha's pendant (possible spoilers)

Maybe it was something that stopped the simulation. Like a key or something.

My own dumb theory:

Since IZON is frequently mentioned, and they're a big player in Zero; Kate could have been a mole for them. As for what was on it, since Sasha is a notorious hacker on genius levels; perhaps she developed a system that would have been useful for them. As for Kate herself being shot, they probably knew what they were looking for and got rid of her once she wasn't of use to them anymore.

"I'll go,because I am Cinema!" - Ben (Man Bites Dog)

I think any creature that exited the hypercube would be seen as dangerous.

"I am like Cryptonite to men. Cryptonite dipped in cellulite!"