 The characters would also frequently travel to alternate dimensions to battle dinosaurs, zombies, and robots.The aforementioned Time Closet was the catalyst for several episodes involving time travel, to and from both the past and the future.In these episodes, regular cast member George Alexander played Mr. Puttnam's grandfather in sepia-toned scenes set in the early 20th century as well as an older Mark in the future, who would eventually have a daughter named Leonard (who, in turn, travelled back in time to meet her father as a young man) and take over control of the emporium.