Marcus lives

Rufus needed contact with Mac to consolidate what happened recently. Things had gone awry with his irrational, savage side. Also, a third dimension had appeared in his character, the emotional quotient.

Rufus still had the Mac craving deep in his cortex, so he 'plugged in' more regularly, hoping Mac would put him straight.

Rufus now spent many hours in the laboratory. His tutors were impressed and the word 'genius' was floated. However, the true genius was Marcus, enhanced by his creation now called Mac, working through Rufus.

Marcus was alive in Rufus!

(Maybe cutting his cock off wasn't so smart!)