Discovery+1

It's been tipping over for 800 years - what's the gravity-defying magic behind Pisa's leaning tower? And, how are chocolate digestive biscuits manufactured.

How did the ancient Greeks invent parchment with techniques still used today? And how do they make shuttlecocks, the fasting moving object in sport.

How do they make smooth writing ballpoint pens that don't leak or fade? And, how do they make pizza for soldiers on the frontline.

In Cremona, how do they make modern violins that sound as good as the legendary Stradivarius? And, how do they build houses with volcanic rock.

Dr. Jeff and Petra train new vets at a wildlife sanctuary in Mexico. While there, they spay an endangered jaguar, and help an injured osprey.

Jeff. Dr. Jeff performs a surgery he'd never done before on a dog with laboured breathing. Meanwhile, Dr. Baier saves some neglected ornate box turtles.

A dog is rushed to the clinic after being hit by a car. Four rats must be neutered before adoption and a little girl rescues kittens in Grand Junction.

He's In The Water! When Wizard deckhand Lynn Guitard goes overboard, Keith and Monte scramble to rescue him. Sig lets Sophia prove herself at the Russian line.

Greenhorn Todd's abscessed tooth forces Rick to consider a costly return to port. Sig gives protégé 'Bob' the helm for her first-ever opilio season.

As Arctic ice wreaks havoc on the fishing grounds, Rick risks losing a fortune in crab pots. Johnathan tests the Time Bandit's reinforced bow.

Those In Peril On The Sea. Captains Sig and Sophia shift their strategy as injuries plague the Northwestern deck crew. Jake loses power in heavy seas on the Cornelia Marie.

Sig and Sophia score some hybrid crab, but a tank imbalance risks capsizing the Northwestern. The Time Bandit crew races incoming ice to get OJ home.

Sig races to jettison pots to repair a flooding compartment below deck. Rick enlists the Time Bandit to hide hot fishing until Jake calls their bluff.

Tony digs out a dozer and two trucks in the Midas Cut. Parker pushes to get his second wash plant running. Buzz struggles to assemble a new plant.

Builder Chase Morrill and his team rebuild an old oyster shack for a working farm. They have their tightest deadline to date and a budget of only $25,000.

Two renovators have purchased land in a remote part of Colorado. They plan on using a rammed-earth process to construct all-natural walls.

Stung by Patrick's criticism, Allison crafts debris into a fishing net. A tropical storm pounds the survivalists. A team must abandon their camp.