Sam Anderson

Basements are a firefighter's worst nightmare.

Basements are a firefighter's worst nightmare.

If the floorboards collapse, they'll be trapped in the suffocating heat of a fiery pit with no escape. This kind of accident happens often enough that firefighters have a word for it. They call it a widowmaker. As the risk to human life continues to grow with each new fire, Rob is under serious pressure to solve this case. And frankly, he's overwhelmed.

If the floorboards collapse, they'll be trapped in the suffocating heat of a fiery pit with no escape. This kind of accident happens often enough that firefighters have a word for it. They call it a widowmaker. As the risk to human life continues to grow with each new fire, Rob is under serious pressure to solve this case. And frankly, he's overwhelmed.

This latest fire at Danielle's place is, once again, outside the area that police have been surveilling.

This latest fire at Danielle's place is, once again, outside the area that police have been surveilling.

Do my ears deceive me? Or is the proudly independent lieutenant finally ready to ask for help? So far, Rob's been resistant to accepting assistance from the FBI. But now, it's obvious even to Rob that it's time to call in the cavalry. So when he gets a call from an FBI boss, Rob says, okay, come on down to the scene. Let's talk.

Do my ears deceive me? Or is the proudly independent lieutenant finally ready to ask for help? So far, Rob's been resistant to accepting assistance from the FBI. But now, it's obvious even to Rob that it's time to call in the cavalry. So when he gets a call from an FBI boss, Rob says, okay, come on down to the scene. Let's talk.

He now has the full might of the FBI behind him. What Rob once described as a neighborhood problem has officially blown up. And it won't be long before they're on the trail of some very juicy new leads.

He now has the full might of the FBI behind him. What Rob once described as a neighborhood problem has officially blown up. And it won't be long before they're on the trail of some very juicy new leads.

Soon after Lieutenant Rob Handy accepts the help of the FBI, a huge joint task force is assembled.

Soon after Lieutenant Rob Handy accepts the help of the FBI, a huge joint task force is assembled.

Among the dozens of agents told to join the task force is Ken Williams, the local man we met earlier who left his grill to run to the fire. Because Ken Williams is more than just a neighbor of Danielle Sink. He's also a special agent with the FBI. And now his bosses want him to investigate the case unfolding in his very own neighborhood.

Among the dozens of agents told to join the task force is Ken Williams, the local man we met earlier who left his grill to run to the fire. Because Ken Williams is more than just a neighbor of Danielle Sink. He's also a special agent with the FBI. And now his bosses want him to investigate the case unfolding in his very own neighborhood.

At first, Ken is resistant to the idea of joining the arson task force because he already has his hands full with another case.

At first, Ken is resistant to the idea of joining the arson task force because he already has his hands full with another case.

Ken has a source who's a member of a terrorist group. And he's paying this source for information.

Ken has a source who's a member of a terrorist group. And he's paying this source for information.

The source has just given Ken a new lead.

The source has just given Ken a new lead.