The StoryBots brave a castle on a dark and stormy night to understand how eyesight works. Maria Bamford guest-stars as an eccentric scientist.

The StoryBots jump into a vending machine to find out where candy bars come from. Alyssa Milano guest-stars as a chocolatier.

We use the toilet every day, but how does it work -- and where does our waste go? Jason Sudeikis guest-stars as a plumber in the know.

To see how cell phones work, the StoryBots hop inside one. Jennifer Garner guest-stars as a cell tower switching-station operator.

A trip to a landfill teeming with trash teaches the StoryBots the importance of recycling. Tony Hale guest-stars as the owner of a sorting facility.

No two people are exactly alike, thanks to a little thing called DNA. Reggie Watts guest-stars as a nurse who explains it all.

The 'Bots blast off into outer space to learn how planets are made -- and what they're made of. Zoe Saldana guest-stars as an astronomy professor.

After tumbling into a tuba, the StoryBots enter a magical, musical wonderland. John Legend guest-stars as the King of Music.