One was an insurance renewal.

And here is the thing that I did not understand until a lawyer explained it to me four weeks later, and that almost nobody outside transactional practice understands.

Signature pages travel.

It is entirely ordinary, in commercial practice, for a signature page to be executed separately from the document it belongs to, held, and attached at closing.

There are firms that do it hundreds of times a week.

The whole apparatus runs on the assumption that the person holding the page is honest.