"The Prethoryn Swarm begins with a notice about 'Subspace Echoes'; the only choice begins an event chain called The Coming Storm. Shortly thereafter, more event notices will mark the estimated location of the Swarm's arrival via situation log; approximately half a dozen systems near the edge of the galaxy will be highlighted. Some time after this point, the vanguard force will arrive and establish the Swarm "homeworld". Unfortunately, this is just a precursor, as the Scourge of the Void event chain will shortly begin, marking the arrival of the main Prethoryn force."