Thirdspace cruiser

Amras-Arfeiniel (To quote the most spine chilling line of dialogue/monolgue about the terrifying Thirdspace Aliens):

"We tried to stop it... tried to warn you...... we failed.And now it is too late. The door is opening."

(Ambassador Delenn: "Who are you?)

"An echo of what was... a memory, a warning embedded in the thoughts of each generation and passed on to the next. We were exploring memories when the device was found, that activated this memory, this message."

(John Sheridan: "Lyta once told me that there might be some leftover programming still inside her put there by the Vorlons when they took off for the Rim. This could be part of it?" )

"Yes. A race memory. Our great mistake... our failing. And now your failing. The error is compounded."

(Ambassador Delenn: "What mistake?")

"The first one. The one from which all mistakes proceed. The Error of Pride."

[describing how they traveled to many worlds, before creating the Thirdspace Gateway Artifact]

"We had traveled to a thousand worlds. We brought order, discipline. We appeared to them as beings of light. They saw us as emissaries from the universe. They saw us as gods. And we, in our pride... began to believe them. We believed that we were superior to the universe that gave us birth. We believed we could transcend this dimension... that we belonged to another higher plane. And in the end, in terms you can understand... we resolved to storm the gates of Heaven itself. We applied all our wisdom, all our knowledge... to opening a door to another dimension... a place we believed was the well of souls... the foundation for all life. We would touch the face of God... and in so doing, become gods ourselves. We forgot that a door may swing in two directions. We were so concerned with getting out that we never stopped to consider... what we might be letting in until it was too late."

[describing the Thirdspace Harbinger Aliens true intentions]

"They are a power beyond comprehension... A hunger beyond understanding...  They are anti-life itself, older even than we were. Telepathic, all of  them, they modified the gate so that it enhances their telepathic  impulses, created an army of our own people willing to die for them. We fought them back, disabled the device... but those of us controlled by their influence... dropped it into hyperspace before we could stop them. Hid it from us." 

(John Sheridan: "What do they want?") 

"To destroy all life that is not their own. They believe only they have the right to exist in the universe... that all other life forms are inferior, and must be exterminated. In their own universe, they have destroyed thousands of races... and continue to destroy thousands more. Because of our pride... they know we are here. They watch us from within their dark cities... waiting for the chance to come here... and destroy."

(Ambassador Delenn: "Why can't they make a gate from their side?")

"The door must be open from both sides. Close this one, and they cannot come through. We've been search for it for centuries. Hoping to find it and destroy it. We feared this day would come. They MUST be stopped... or hundreds of worlds will die!"

(John Sheridan: "How?")

[Lyta walks towards Sheridan and mind meld-links with him, to show him how to stop the sinister, other-worldly, alternate dimensional Alien Invaders]

"Learn..."

- The Vorlons, speaking through Lyta Alexander (from the 1998 film "Babylon 5: Thirdspace")