Booking through Thursday

This week's question is:

What’s the worst typographical error you’ve ever found in (or on) a book?

Well, as a proofreader and editor, perhaps I should steer clear of this one.
Siht happens.

But since you ask ... this morning, I finished reading William Boyd's spy novel, Restless. It was superbly written, but so badly punctuated I frequently found myself re-reading passages to make sense of them.

And three or four years ago I read a book (title forgotten) which I don't think had been edited at all, despite a reputable publisher's imprimatur.
So I got out my red pen and began marking it up, with the vague idea of sending my corrected copy to the publisher and asking for a job. But in the end, the story won me over and I abandoned the project.
There were errors all through the Harry P books, too.

There are lots of people involved in getting a book to the shops.
By the time a proofreader gets her or his hands on a manuscript, it will have been worked over by a structural editor, and then a copy editor. The proofreader may mark up an error on a manuscript, and then someone else will have the job of making that correction - or disagreeing and not making that change - and then it may go to yet another proofreader for a final read-through. The author gets a say in it all as well. And then there is the team working on the cover artwork, which may be perfunctorily checked by yet another editor or proofreader ...
Every time the manuscript changes hands, there is potential for slip-ups.
All the people I have ever worked with, in newspapers or books, have always been caring to the point of fastidiousness over their work, and mortified to find errors, however minor.

One final point: it would have killed me to let Joan Didion get away with 'Play it as it Lays'.
Lays what? Bricks? Eggs? Carpet? Some pick-up in a bar?