en.wikipedia.org/wiki/If_Anyone_Builds_It,_Everyone_Dies

This is a precise bibliographic claim, so the publisher’s own edition metadata is the strongest evidence. Hachette Book Group’s official page for ISBN 9780316595643—the same ISBN shown in the article—lists the hardback as having 272 pages. The UK publisher listing for the hardback edition likewise gives 272 pages. That directly contradicts the article’s infobox entry of 256 pages.