Thanks to stress over having a baby, Howard has started to panic... and he makes an impulsive purchase. Maybe that purchase is something that will actually be helpful for the baby, but my guess? Probably not so much.
It's very simple. Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and, as it always has, rock crushes scissors