User blog comment:Brianbreed/The Biggest Single Plot Hole in Mass Effect 2/@comment-1462101-20110910161353/@comment-399234-20110911033106

Even drama begins to lose its effect if a story doesn't adequately explain how an important event was allowed or enabled to occur; I suppose it's "implied" that there was another relay in the galactic core, and that the Omega-4 relay entered into a two-way connection like the other relays do, but I don't think we ever actually see that "partner relay."