Marcus leaves his home in Bluff and embarks on the start of a 100-day journey around New Zealand by rail. From Invercargill - the most "trained-up" place in the country - he catches a coal train to the tiny town of Ohai and stays with rail worker, and train painter, Tony Bishop. In Winton, Marcus investigates Minnie Dean's obsession with trains, then tracks down the old line to Lake Wakatipu and travels on the country's most famous train.

From Queenstown, Marcus follows the old Cromwell line to Dunedin, variously using pedalo, bicycle, rubber dinghy and jigger. He stays in New Zealand's most spectacular farmstay and meets a survivor of the Hyde train crash who vividly recalls the horror of that cold June day in 1943.

Marcus investigates the Seacliff Lunatic Asylum fire, one of the least-known New Zealand disasters, despite it claiming 37 lives. He also gets a handle on railway cups, talking to three women who used to mak them in Temuka and goes on an archaeological dig to find a few of his own.

After arriving by train in Otira, Marcus spends some time helping to run the town with the couple that own it. He then heads to Denniston - a remarkable West Coast town above the clouds - and stays with one of the few families who still live there.

Heading out of the West Coast on a coal train, Marcus meets some miners in Reefton, finds out what happened to Nelson's trains, celebrates Kaikoura replacing rails with whales and ends up in Picton in a subway.

From Wanganui, Marcus travels by steam boat and milk train to Whangamomona. He goes to bed in a town of 40 and wakes up the next day to find he's on of 6,000. He then catches his first rail enthusiast train, with mixed results, and stays at the world's most unusual marae which has its own secret rail network.

From Taumaranui to Palmerston North, Marcus celebrates the Main Trunk Line, ponders the perplexing Raurimu Spiral and taks to people still affected by New Zealand's worst rail disaster, Tangiwai. Finally, he has a fist and chip feed with a family that has its own railway, hundreds of steam engines and, surprisingly, a marriage that's still intact.

Every day, hundreds of Palmerston North people catch the train to Wellington to work. Marcus partakes in some of their rituals and discovers that the capital is full of rail obsessives. He finds an amazing suburb of railway houses before unveiling the rail miracle that is the Rimutaka Incline.

In Pahiatua, Marcus explains why railcars are the rolling stock that really spins his wheels. He spends the night half a metre from a busy rail line, rides on the country's most successful train... in Hastings, visits the scene of the Kopuawhara flood and, in Gisborne, takes a unique ride on the rails right across the airport runway.

Marcus follows a log as it is felled in Kaingaroa Forest, loaded on to a train and taken to Mt Maunganui for export. He vists the historic gold trains of the Karangahake Gorge, meets Coromandel livewire Barry Brickell who built his own narrow gauge railway and, in Hamilton, discovers an extraordinary collection of railway exotica.

Marcus hitches a ride on a loco from Hamilton through the Waikato. A visit to Glenbrook is followed by a morning with singer Jordan Reyne who lives in a campground and writes songs about trains. Britomart, broadcaster Merv Smith and Westie comic and local body councillor Ewen Gilmour also feature.

Marcus gets to ride the one train that's eluded him until now. He heads for Northland via Helensville where he meets the women who used to run the station tearoom. He explains the world of "foamers" - railway obsessives who have crossed the line - and goes as far north as the rail ever went. Finally, Marcus walks the line - literally - to Opua.