The Silver Menace

"The Silver Menace" by Murray Leinster is a science fiction story where wealthy steamship owner Alexander Morrison and his daughter Nita encounter a strange, jellied substance that slows their yacht. What starts as a puzzling situation quickly turns dangerous as an invisible force and foul odor plague their vessel, eventually stopping them completely, spurring a desperate call for help. Meanwhile, Flight Commander Richard Davis answers the call and sets out in his seaplane to investigate. The story escalates as they discover the "Silver Menace" is much bigger than just their yacht, posing a serious threat to everyone, which forces Morrison, Nita, and Davis to step up and face it.