In a scientific face-off, Mark goes head-to-head with NileRed and Kevin the Backyard Scientist to find out which is more destructive: acid or lava.

To stop the sneaky squirrels from raiding his bird feeder, Mark builds a challenging eight-part obstacle course in his backyard to try and slow them down.

Mark throws an epic birthday party for a deserving teen, complete with record-breaking devil's toothpaste experiment - the first of its kind.

Step right up and learn which carnival games are actually winnable and which ones aren't, courtesy of Mark... and a friend from the New York Mets.

Mark's robot Dom is really good at setting up dominos. But can he fill a warehouse with a mural made up od more than 100,000 of them in just 24 hours?

Mark has 30 minutes to find all nine product designers hidden inside the CrunchLabs warehouse - and they're allowed to fight back with blasters!

In honor of the historic Perseverance Mars rover landing, Mark talks to some of his old friends at NASA and suits up to see the actual rover up close.