To answer an assortment of science puzzles, Mark takes his experiments to the next level — on top of a moving train and up high in a hot air balloon!

Now it's lasers vs. lightning in a showdown to find out which one is more destructive. With a series of tests, the CrunchLabs crew declares a champ.

Actor Macaulay Culkin joins Mark as he unleashes upgraded bait packages full of glitter — and stinky fart spray — to lure potential thieves.

Mark's running for his life while being hunted down by an expert tracking dog. Can he engineer some distractions to throw the dog off her game?

Let the games begin! From a high jump to a spinning balance beam, Mark's set up a series of backyard battles for squirrels competing for the Walnut Cup.

One small step in space, one giant leap for taking a selfie. Mark preps a satellite to snap pics of the Earth photobombing the selfies sent by his fans.

Get ready for liftoff! After three years of work and spending millions of dollars, can Mark ensure his selfie-taking satellite has a successful launch?