In Dragonfall, the Harfeld Manor is a front for the underground laboratory complex built by Adrian Vauclair, with Audran helping out as security chief and APEX in charge of Matrix security. On the Berlin crew's first venture there, Monika was killed. The Berlin Crew revisits the manor at the end of Dragonfall.
In the epilogue, Hans Brackhaus reveals that it was him who tipped off Green Winters regarding the manor's hiding of secrets.