Borg Queen and Future Admiral Kathryn Janeway in “Unfinished Business”

You're asking me to believe that the incorruptible Kathryn Janeway would betray her own crew?

Not betray them. Save them from themselves. I brought technology to help Voyager get home. But the Captain is arrogant, self righteous and her officers are so blinded by loyalty that they're prepared to sacrifice their lives just to deal a crippling blow to the Borg.