In Utah, Riley joins a crew of more than 300 engineers, contractors and laborers as they gamble on an innovative installation technique: demolishing a crumbling concrete bridge and installing a new throughway bridge in just four days (WTF!). This fix involves huge remote-controlled trailers, enormous hydraulics, and a 4 million-pound, five-lane bridge that must be transported almost two miles before it is installed in one piece on Interstate 80 in Salt Lake City.

WTF rides the rails in the City of Brotherly Love. While there, Riley teams up with crews of the nation's fifth largest public transportation system, Philadelphia's SEPTA, to find out what it takes to keep 2,200 miles of tracks safely running. The team must replace a three-mile section of 80-year-old high-voltage wire. It's a risky operation, with live wires just an arms reach away. Then, Riley heads to the garage to work on a train with a malfunctioning automatic control system.

Go on a cruise. They said: In the Bahamas. It'll be a lot of fun, they promised. Mid ocean in the Caribbean, its a race against time. This may be Paradise, but Riley's not on vacation. He's on his way to a titanic fix. An enormous 90,000 ton cruise ship is steaming towards one of the worlds largest dry docks. They need to install a new power plant an enormous diesel generator, but first they have to land this ship. That's when the fun starts Then things get a whole lot tougher Its all hands on deck as a huge crew opens the hull pulls out the piping, makes room for a two story addition and struggles to cram a massive new 320 ton generator inside the ship then puts it all back together And in record time! In just twenty days this liner is taking on its next bunch of customers and if the ship is not ship shape there's likely to be a lot of harsh words spoken on board.

Riley travels to Portsmouth, R.I., where residents are setting up a 115-ton wind turbine that will provide years of clean energy. The constant blowing wind will fuel the rubine, but how do you raise giant blades in the midst of these unpredictable winds?

Sean Riley puts on his radiation suit and heads into the radiation zone for his next tough fix, replacing a steam turbine in a nuclear power plant to boost its energy-producing capacity.

Riley is going to new heights. He'll hang over the edge of Las Vegas' tallest building to fix the X-Scream, a thrill ride on the Stratosphere. One of the critical safety measures needs replacing, and Riley joins the ride's head of maintenance on the very edge of the track, 800 feet above the ground, to make the fix. Then he'll dangle 500 feet over the side of the Hoover Dam to retrieve trash. Upriver from Niagara Falls, he'll hang over an unstable, overgrown cliff to eliminate loose rocks.

The Bay Bridge joining Oakland and San Francisco made headlines in 2009 when it was shut down for a major renovation. To make the fix, Riley joins the engineering team tasked with cutting a football field-sized section of roadway from the bridge and replacing it - in just 72 hours! With traffic halted and the world watching, the team encounters some unexpected challenges. A crack puts the operation on hold and requires custom-made colossal steel brackets. The clock is ticking.

A fishing boat that ran aground in the treacherous Bering Sea is potentially a rusty death trap for the thousands of seals soon to arrive for mating. Sean Riley joins a crack crew of salvage operators who have only a few weeks to strip down and slice the boat into bite-sized bits. The rusty steel has to be removed by a jury-rigged cable stretched from a crane, because vehicles are forbidden on the ecologically sensitive beach.

Three days, one 300,000-pound bridge, two buildings, and mere inches to spare - there is no room for error on this next-to-impossible fix, as Riley helps lift a bridge between two buildings. Working in downtown Salt Lake City - with a commuter train running through the worksite, power lines all around, and five stories of parking garages below - two massive cranes will work in tandem, and all work has to be done in the dead of night.

Riley joins a team of industrial divers on the Caribbean island of Curacao to salvage and repair the 50-ton rudder of a ship carrying $3 million worth of iron ore.

Riley travels to Las Vegas to help high-flying Cirque du Soleil solve a real showstopper of a problem - one of the world's largest, most technologically advanced stages is broken. To make the repair, Riley and team have to lower the 80-ton stage and take a look inside - a process never before attempted. While in Sin City, Riley helps repair some of most amazing spectacles on the Strip, including the world's largest video screen and high-tech water cannons in the Bellagio fountain.

Riley heads into the remote jungle to help a team of rocket scientists and engineers launch a new two-ton satellite with a price tag of more than $1 million into orbit.

Sean Riley helps swap out a 38-ton engine on one of the largest ships in the Gulf of Mexico. The fix must be done in the middle of the gulf—and with swells, wind and rain, things can get complicated.

Sean Riley joins a team of engineers and mechanics as they attempt to fix a damaged Boeing 767 jet. This is a crucial fix—taking a jet apart and putting it back together is a complex, three-week operation, and the smallest mistake could have huge consequences. As the new guy on the project, Riley is given an unpleasant task to prove his mettle—disconnecting a lavatory tube