George is thrilled to visit Pizza and Einstein's Space Center to help solve a problem with the Mars rover. But a sleepy monkey falls asleep and wakes to discover that he and the Man with the Yellow Hat are going to Mars! Can the curious little monkey figure out what's been gumming up the rover's controls? Or was it all just a wonderful dream? / When the grocer runs out of masa (cornmeal), George and Marco are worried they won't be able to make Marco's famous tortillas for his abuela's birthday. Thankfully, Uncle Enrique makes it his mission to find the key ingredient. During their ride on the "Tortilla Express," all three learn where masa comes from and how it gets from the farm to Marco's table.