And then the group proceeded to swim underwater, in an exciting swim-chase sequence through the flooded ship as they were pursued by aliens and attacked in an "ambush" of face-huggers from multiple pods.[In the original novel, Shears was a dedicated officer, but here, he""s a typical Hollywood hunk character.Although pursued, all of them manage to defend themselves, reduce heir fragile adversaries to dust with a whack from an umbrella, and escape back to the rocket ship shell - a dissolve moves from one scene to the next.Gene Kelly served as the film""s principal star, singer, athletically-exuberant dancer and energetic choreographer - he even directed the sequence surrounding "Embraceable You.At lunchtime, he visits Mulwray""s "Water and Power" office, but the engineer is not in.Lying to pretend that he has an appointment (he tells Mulwray""s secretary (Fritzi Burr) that "it""s a personal matter"), he snoops around the office (he sees a framed picture of Evelyn next to a stallion on the desk) and opens up Mulwray""s desk drawers.