Stargate Atlantis 4x11

Video Title :	Stargate Atlantis 4x11
Description :	Stargate Atlantis SciFi Stargate Atlantis space battle season 4 Jumper Replicator Home World WOW
Views :	1448
Rating :	3.60
Keywords, Tags :	Stargate Atlantis SciFi space battle season Jumper Replicator Home World
Video Length :	2 : 24

Comments :

to destroy the replicators

Can someone explain to me why this battle took place, and why they blew up the planet?