Ok this is what Mark should do now

So, right, ok, he should go downstairs and go stand by the front door. He should tell his sister a message for other Mark, then go outside. Devon should repeat the message to other Mark. He should reply and go inside. Then she should repeat his message. They should do this for about 1hr. The last 15 minutes, just shoot guns and stuff inside Lumon to exfiltrate Gemma. ITS SEVERING TIME.