Of course, he knows that Montana Wildhack is back on Tralfamadore raising their child.
The magazine, however, claims that she has drowned in San Pedro Bay.
The magazine ran this article because they wanted to use photographs from porn flicks that Montana made when she was a teenager.
Seeing his interest, the clerks send Billy back to the rear of the shop, where he can watch a film with Montana Wildhack in it.
He goes, but he doesn't really watch – instead, a clerk leads him over to "some really hot stuff they keep under the counter" (9.31.4): a picture of a woman trying to have sex with a Shetland pony between two Greek columns. (Just like Roland Weary's picture in Chapter 2, Section 22.)