Mark Lilly mistakenly gets the zombie Tyler Mason a job as a window washer at the M.B.D.. He gets caught up in a hostage situation when he cannot control his urges and starts eating the brains inside. Mark gets there and talks him into surrendering himself.
In "Little Ship of Horrors", Mark tries to sneak in the M.B.D. to get brains for Randall Skeffington. Francis Grimes, who works as a night guard there, mistakes Mark as a temporary cleaner and lets him in.