The wage-system of modern England is a little difficult to explain in three words even if you understand it—which the children didn’t.
The Story of the Amulet opens on an unexpected note, with Edith Nesbit cheerfully informing readers that the first book of this series, Five Children and It, had ended in a “most tiresome” way. (The perhaps unexpected long term result of this was that it took me years to read Five Children and It, since I encountered The Story of the Amulet first and took Nesbit at her word. I note this as a caution to authors planning on inserting derogatory comments about their earlier works into any later novel.) To correct this error, Nesbit has the four children meet the Psammead, that magical, wish-granting creature, in a pet shop, quite by accident for a second time. The Psammead, apparently deciding that even they can’t be as bad as the pet shop, begs the children to buy him.
And although the Psammead still can’t grant their wishes, it can and does urge the children to buy an amulet with magical powers. The amulet does have one tiny, teensy problem: it’s broken. To fix it, the four children are going to have to do a bit of traveling in time and space, and also try chatting with the upstairs neighbor, an antiquities expert.
[And learn how future societies still worship the name of H.G. Wells]