3.  Anna reaches the Central Tower where the 'Old Man' is at.  Worrying that there could be possible observation and retaliation by Unit 73 if they know what she is doing, she tries to cover her trail by going to the main office and asking for directions to the barracks where her old comrades were stationed, to make it appear that was her only reason for being in the area if she is being observed
.
When the officer at the desk makes the joke 'be sure to tell squad 6 isn't goofing off, the Old man  can see them from here' she realizes he is there in the main office at the top of the tower.  Anna slips into the ventilation system through a vent in a maintenance room/restroom/closed concession stand etc and infiltrates to the top of the tower.  Startling him at his desk-she tells him she has information about Unit 73, he goes from startled to interrogation mode-asking her everything he can about the mission to the ruins and what U73 was up to.  Handing him the crystal shard she was hiding-he smiles and tells her it is actually a device that has the 'addresses' of the worlds U73 wanted to explore and with that evidence he finally has what the heads of the Order need to finally disband U73 once and for all.  He then shows her a secret elevator shaft to the lower levels of the tower and tells her to leave quickly and go straight to the barracks to visit her old friends and tell nothing of their meeting.  

He also adds that orders will be swiftly given to transfer her to the new ship that recently arrived on the 4th planet called the Bronze Voyager-a large interplanetary ship that's about to leave for an ambitious expedition to one of the outer planets-a gas giant known as the Ringworld.  He tells her that it is for her own safety-by sending her off on the expedition due to her known skills as a cool operator under pressure-she will be 'out of sight, out of mind' for U73 while the Order tries their staff and begins disbanding their organization to lessen the chance of possible retaliation if they realize who has helped to drive the final nail in their coffin as a section of the Order.
Anna steps into the elevator and the mission ends.