Perfect Mysteries:
Cassandra de Vreis

Just your average middle aged evil women, right?  Wrong!  There are some things about Cassandra that will make your head spin!  Here they are!
When you pick up this replacement necklace in the Attack Ship mision, it will have a password in it, which has been translated to "I am Ozy Mandias," a poem about death being inevitable.  So Cassandra knows she will die.  Weird...
In dataDyne: Extraction, if you are lucky, you can get Cassandra's offiec keycard.  In her office is a grenade, which you use to blow up this wall.  Why?  Keep reading.
In there, there is a Dragon, with a whole lot of bullets, and this level's piece of cheese!  The Dragon is probably meant to be used on her bodyguards later on in the mission.  But that's not all...
The keycard also unlock one of the doors on the main floor!  And in it, are the people that are in the cut scene!  There are the two bodyguards that Joanna shoots as she jumps into the plane!
And, the ominous Mr. Blonde is also in this room!  In this picture he looks so... ominous I guess.  He's pretty tall too.