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The Nintendo arcade game that Mark Greene is playing is Killer Instinct.

Carol: It's darkest before dawn. This is a reference to the proverb "The darkest hour is just before the dawn." Thomas Fuller, the English theologian and historian, may have been the first person to commit this notion to print; his religious travelogue A Pisgah-Sight Of Palestine And The Confines Thereof (1650) contains the line "It is always darkest just before the Day dawneth." Many, many authors and poets since have incorporated a version of the adage into their writings.

Carol: Like Thelma and Louise, man. Susan: More like Lucy and Ethel. Carol is making a reference to the 1991 film Thelma and Louise, starring Geena Davis and Susan Sarandon, about a couple of women whose weekend getaway turns sour and transforms the two into outlaw heroes. Susan is making a reference to the 1950s situation comedy I Love Lucy, starring Lucille Ball and Desi Arnaz, as well as Vivian Vance as Ethel.