Welcome to a new episode of The Investigation.

I'm your co-host, Chris Vlasto, senior executive producer here at ABC News, and I'm joined

today by our guest co-host, Matt Mosque, one of our senior investigative reporters here on the

task force.

We're joined by the co-founders

of Fusion GPS, Glenn Simpson and Peter Fritch, their new book, Crime in Progress, Inside the Steel

Dossier, and the Fusion and GPS investigation of Donald Trump is out today. And we welcome

both of them here to the investigation. Before we begin, I've obviously had a lot of guests that I've

known for 20 years, and I must disclose that I've known Glenn for about those 25 years when we began

as reporters in Washington. But let me ask you about this book. You guys have remained quiet

for most of the time since the dossier first came out. And this is the first time

you've actually talked about your experience. When you set out to do the dossier, what was the

purpose of it? The story of the dossier is actually of a long investigation that began in

September of 2015 and had nothing to do with Russia originally.

We were asked to look into Donald Trump's business history and business career,

and the book describes this at some length, and it was actually an assignment from the Republicans

to research Donald Trump's business career.

Over the first seven or eight months of this work during the Republican primaries, we kept coming across weird connections to Russia and Russians.

You were hired by the Republicans to do this dossier. Right. What, Peter? Well, I was just going to correct the record there a little bit.

We weren't actually hired to do a dossier.

Okay.

And we didn't do a dossier.

...