Between the fourteen-legged metal eaters, a prison break of shape-shifting Dreephars, and flying manta ray like creatures, life is never dull for America''s first outer-space family! But while the lost Robinsons continue their interstellar journey to return home, swords and sorcery meet science fiction as the familial explorers team up with medieval knights and return to Earth - in the twelth century!

With the help of an advanced group of alien beings, a little ingenuity, and a lot of luck, the Robinsons have managed to traverse dimensional rifts and vast swaths of space to make their way back to our solar system! But something has gone wrong! Their time-shift mechanism has malfunctioned and sent them careening into Mars! With repairs to their ship underway, the Robinsons notice that this isn't the Mars that they know, but Mars from untold ages ago! Join the Robinsons as they come face-to-face with Martians! Will they survive Mars and make it back to the present, or be forever lost in time?