密实

密 = 宀 + 必 + 山 : Marilyn Monroe (mi) is secretly (密) making out with her secretary (密) Khubilai Khan (必). Because it has to be a secret (密), they meet in the space station's bathroom (Ø4) and hide under a huge graduation cap (宀). Just to be sure Khubilai Khan has two forks (山) in his hands to attack anyone who might enter and see them.

实 = 头 + 宀 : Sherlock Holmes welcomes professor Skull just inside the entrance of the space station. Professor Skull has not a complete head but only a skull, and a solid understanding of solid state physics. She really is an honest person and still wears her graduation cap.