We focus on the part of the internet that most people don't know about.

It's called the dark web.

Undercover in the furthest corners of the dark web,

US special agents are on a mission to locate and rescue children from abuse.

Move in now.

Police!

From the BBC World Service, World of Secrets,

the darkest web follows their shocking investigations.

Listen on BBC.com or wherever you get to your BBC podcasts.

Before we get going, just to mention, this episode includes strong language,

descriptions of violence, and language some listeners may find offensive.

Following the police visit, disappointment hangs over our house.

I can't say I expect much from the police at this point, but I really thought what Colin handed over to them were meaningful lines

of inquiry that they would feel compelled to look into.

To me, the evidence that this group of suspects should be investigated again by police was

significant new information.

And if there's anything that would make them take us seriously, it would be this.

Colin is stunned.

Jackie and Sean are stunned.

But my dad?

For him, there's more going on.

I am always desperate to try and conclude this before I pass on.

...