After stops in Sun City and Tombstone, Arizona, Jack and Michael go to Las Vegas, where a surprise guest could ruin Jack's "lads and dads" itinerary.

Jack treats his father to a luxurious birthday trip to Istanbul, where they visit a hookah lounge and Michael recalls a wild night with David Bowie.

In Phuket, Jack tries to get his dad to loosen up at a full moon party, then seeks his emotional support in a floating football match.

In Siem Reap, Jack upsets Michael at a puppet show, then Jack observes rats that help clear minefields. Later, the pair seeks some peace in Vietnam.

Jack and Michael honor Michael's parents in a ritual and visit a performance artist in Hanoi, then reflect on the impact of their journey.

Now in Cambodia, Jack and Michael take a primitive train ride. Jack obsesses over finding food his dad would enjoy, and they visit Angkor Wat.

Michael bosses his son with "dry history" in Germany's Bavarian Alps, while Jack tries to liven up their first stop with motorcycles and skies.

Jack and Michael channel Harry Houdini and take a boat ride in Budapest, and then have an odd border control experience on a road trip to Transylvania.

In Romaina, Michael and Jack pay a visit to "royalty" and an unusual cemetery. Later, they go to a little visited Moldova to meet Sunstroke Project.

Michael puts Jack through military training in Kiev, and then they head to Chernobyl before Jack drags his dad to a clown festival in Odessa.

Jack and Michael begin their journey in Bangkok and immediately clash over accommodations, then visit an odd temple and attend an elephant polo match.

In Bangkok, the Whitehalls patronize an unusual doll shop. An annoyed Michael needs time away from Jack, so Jack goes off on his own to try parkour.

In LA, Jack and Michael take in some naked yoga, acting lessons and a tour of Compton. Then they ride a bus to Phoenix, where Jack becomes a wrestler.

In Sydney, Hilary joins the boys and goes head-to-head with Jack in cricket, while father and son compete in a drag show and Jack tries speed dating.

Jack and Michael head to Queensland and Uluru, where they meet a senior biker “gang,” celebrate Australia Day and rub elbows with emus and camels.

The boys kick off their final journey with a meal from Gordon Ramsay, then try Morris dancing, tour Winston Churchill’s home and visit Burgh Island.

Jack and Michael herd sheep in Wales, hike the Lake District with llamas, search for "Nessie" in the Scottish Highlands and ride a "Harry Potter" train.

With their final trip behind them, Jack and Michael sit down to reflect on the entire experience and view some of the most memorable highlights.