Poisonous gas vials or capsules (with skull and cross-bones labels) were being applied to research test subjects in tubes - spiders.Elegantly-dressed, high-society opera-goers are leaving after a performance and heading for horse-drawn cabs and motorized vehicles."Plot SynopsisDuring the film""s credits, Walt Disney personally thanks he members of his animation staff:My sincere appreciation to the members of my staff whose loyalty and creative endeavor made possible this production.The desperadoes stealthily sneak on board the train (between he tender, the car attached to the steam locomotive that carries fuel and water, and the express mail car) just before it pulls away.Originally, the screenplay was loosely based on Vincent Sheean""s best-selling autobiographical memoirPersonal History, but then it evolved into an original story/screenplay (crafted by screenwriter Charles Bennett and Joan Harrison).