Shortstop was a classic O'Neill Cylinder, set in a long cycling orbit between Earth and Mars. The permanent population was less than 10% of residents, with the majority at any given time using the station as a long but comfortable means of travel between the two planets. The station was halfway on its way to Earth during the Fall, after which nothing has been heard from it and no one has returned from it.
Plot Hook: Density-scans of the station reveal that while synthetic items are all intact, biomass has been converted into a heterogeneous tissue evenly coating the interior. The leading hypothesis is that a crèche infestation has converted all biological life. Firewall will need a team to investigate, as well as retrieve information from intact systems.
Plot Hook: Shortstop's population was annihilated by a TITAN nanoplague that devours transhuman brains and cyberbrains, a plague that still waits within. Without a transhuman presence the gardens and pets have taken over, creating a new ecology of smart animals and modified plants. The orbit of the station is degrading and it will soon fall to Mars. The Planetary Consortium will reward handsomely anyone who can avert this.
Plot Hook: A massive hole was blown in one of the windows and the station's atmosphere was lost within seconds. Most of the station is preserved, including automated defenses. Even the plants remain, desiccated and leafless but with perfectly preserved stems, trunks, and branches. A Fall war criminal has hidden himself here, a large bounty will be awarded to whomever can kill or capture him.