When an event card's special ability area calls for spawning genestealers (e.g., "Choose a Space Marine. Spawn 2 Genestealers behind him."), are the genestealers drawn from one of the blip decks or do they come from the Genestealers deck?
From my reading of the rules, they come from one of the blip decks. The particular blip deck is determined by which side the Genestealers are placed to comply with the event card's directions.
However, if both blip decks are empty (last location card played), does that mean no Genestealers are spawned?