(NBC News) – On an all-new two-hour “Dateline,” a romantic Mediterranean cruise was intended to rekindle the love between Micki Kanesaki and her ex-husband Lonnie Kocontes, but when Micki vanishes, an investigation reveals secret recordings, a surprising star witness, and an undercover hitman.

Here is a preview of Josh Mankiewicz’s report:

The call came in the middle of the night. It was their friend, in a panic.

SUSAN MCQUEEN: Lonnie was in Napoli, and, Micki had gone missing off the boat. And that’s where it started.

JOSH MANKIEWICZ: And what did you think?

SUSAN MCQUEEN: That was a take a — to the count of three kind of, you know, repeat all of that, let me hear it one more time type of thing.

No matter how many times she heard it, it just didn’t make sense.

SUSAN MCQUEEN: You, you think of all of these things. Everything starts rushing through your head.

Except this was clearly true.

BILL PRICE: I just saw disaster happening, in a foreign country.

SUSAN MCQUEEN: You say, this, this can’t be. This can’t be.

BILL PRICE: I knew it in my heart. There’s got to be another explanation.

There was an explanation, all right. It just wasn’t the one anyone was expecting.

Watch “Dateline” tonight on 22News at 9 p.m., right after two encore episodes of NBC’s new comedy, “Mr. Mayor.”