It was ironic, in a way. In a CK-event or NK-event extinction scenario, all SCPs that could be terminated were to be terminated, so that whatever shreds remained of humanity could have at least a glimmer of chance of surviving in the ruined world.
In a XK-event, all SCPs were set free, so that they might carry humanity's last seeds to whatever wonderlands they would flee to.
A suitcase slammed on the floor next to SCP-073. "Heads up, Cain. You are free, on one condition. Take the suitcase with you. When you see the sun again, open it."
Cain shook his head, sitting in lotus position, eyes still closed. He nodded towards the patterns drawn in blood, covering the walls of his room. "I am sorry, but I shall be staying. Chances to die like this only come once… well, in a lifetime. I will not be left behind this time."
The researcher sat in front of him with a heavy sigh and lit a cigarette, his disability making it a long and elaborate procedure. "Suit yourself. Damn, I should've never taken up smoking."
"Losing hope? I guess I should commend you for keeping it this long."
Cain frowned. "I mean it. For what it's worth, I am honestly sorry for what is happening."
"What, you telling me the apocalypse is your doing?"
"Not quite, but I've dealt with it before. And every island fled away, and the mountains were not found, and the third part of the creatures that had life died." Cain vaguely gestured with his metal arms.
"So we're fucking biblical now and you're the Cain that killed his brother?" The researcher chuckled. "I don't think that took."
"No, I am not. At least, not quite." A weary laugh. "Very well. I swore to take this secret to the grave, but there are more than enough graves now. The job your Foundation does - that it did until now? I have done something similar in the past."
"The past. How far past we are talking about? Before the Beatles?"
"Before music. We had a good group, back then. Yweh, me, Hevel, Lilit, Bright - not your Bright, I'm afraid - Orion, Sela… More, much more, but the others are gone. Even their names, when we failed."
"And you guys just lived for the next n-th millenia and waited for someone to invent television?"
"Only the cursed. Only us that went too far and too deep, and were branded for it. No, I didn't kill Able. But I might as well have."
The researcher sneered, lighting a second cigarette. "Could have shared a bit more with us before this sort of schedule pressure, chief."
"One copy of the 'Containment Procedures' in every hotel of America is not enough?"
"Something may have been lost in the translation."
Cain sighed. "Ten millenia is a long time, child. Even ideas decay. No, you have done a much better job than we have. You have even managed to keep that accursed lizard caged for more than a week."
"Not good enough."
"It is not the end, you know. It was not the end before." He touched his brand. "And the storm will face more than seven thirds, this time."
"I'd really prefer to see for myself."
Cain opened his eyes. "Would you? Would you be cursed? Would you have life itself flee you at every step?"
The researcher leaned up, inches away from Cain's face. "If it saves one life. If it lets one more human be born."
SCP-073 paused for a moment, then laughed. "Yes. That is what I said, then." He stood up. "Shall we, Dr. Kain?"
The dog got up and spat his cigarette. "After you… Senior Researcher Cain."