In this erotic twist on time travel, a brother and sister stumble upon an ancient pentagon that transports them to different eras. Their shared curiosity quickly turns into burning desire as they explore historic settings, their clothes falling off with each jump through time. In the 1950s, they find themselves in a seedy motel room, the sister riding her brother's cock reverse cowgirl while the vintage TV flickers with static. In the medieval era, they're caught by a group of lusty knights, who watch as the brother eats out his sister before they all join in, filling the siblings with their hot, historical seed.