The companion cube cannot continue through the testing. State and local statutory regulations prohibit it from simply remaining here, alone and companionless. You must euthanize it. — GLaDOS
We’re a lot alike, you and I. You tested me. I tested you. You killed me. I ki—
Wait… I guess I haven’t killed you yet. Hm.
— GLaDOS in Portal 2
Food for thought during this next test.
The Enrichment Center reminds you that the Companion Cube cannot speak. In the event that the Companion Cube does speak, the Enrichment Center urges you to disregard its advice. — GLaDOS, about The Weighted Companion Cube